Loosening the nuts before you lift the tires off the ground will make it much easier to remove the wheel. Don't completely remove the nuts; you should just be able to remove them by hand.
Raise your car one side at a time and use jackstands underneath the frame. Simply using a jack is unsafe, and the jack itself will probably get in your way as you move around the car.
Be careful not to scratch the paint as you remove the strut assemblies - there are plenty of exposed bolts and sharp metal. For a better idea of the parts I mention in the directions, click on the pictures below to open larger versions.
- Remove the Wheels
Remove the loosened lug nuts and place them somewhere away from your work area. Take off the wheel and do the same. - Remove the Strut-To-Knuckle Bolts
The two strut-to-knuckle nuts are 21mm in size. The bolts themselves are splined to stay in place, so don't worry that their heads have an unusal shape. Once you remove the nuts, pound on the bolts with a hammer to get them out. Don't worry if the ends of the bolts start to mushroom as a result of your work; if they become too mushroomed to accept the nuts, simply grind them down to size. - Remove the Swaybar Endlink Bolts (If working on the rear)
If you are working on the rear of the car, there is an 18mm nut that attaches the rear swaybar endlink to the rear strut. Remove this nut and put it aside. The endlink itself should easily swivel out of the way. - Remove the Strut Tower Nuts
Use a 15mm socket to remove the strut tower nuts. If you cannot easily reach the nuts with the car off the ground, try loosening or removing them before you put the car on jackstands. - Remove the Strut Assembly
At this point, the strut assembly should be free of any attachments. Pull it off the steering knuckle and remove it from the wheelwell. In order to keep stress on the CV boot to a minimum, support the A-arm by placing a jackstand (or other object) under it after you remove the strut assembly.
Both the strut and spring can be easily replaced at this point. If you are only doing one or the other, simply ignore the appropriate directions. Click on the pictures below for larger versions with labels.
- Compress the Spring
Before you begin, make a note of the relative positions between the top plate and lower spring seat on the strut assembly. This information will save you a lot of time later. Now compress the spring coils on the strut assembly, either with a wall-mounted or hand-cranked compressor. You should compress to the point where the bottom of the strut housing "wiggles" freely. - Remove the Top Strut Nut (with air tools)
Simply use a 21mm socket to remove the top strut nut with an air wrench. If the nut does not seem to be moving along the threads, spray a little PB Blaster or WD-40 to penetrate the threads. The nut should come out easily after a minute of soak time. - Remove the Top Strut Nut (with hand tools)
Use the deep offset box wrench to remove the nut, while holding the bolt steady with the Torx bit. Again, you may wish to lubricate the threads before loosening the nut. Note: A regular offset wrench may not clear the collar on top of the strut. Before you start working at all, test the tool by opening your hood and checking for clearance issues with the strut. - Remove the Strut
The strut can now be pulled free of the assembly, leaving just the spring and the parts on top of the strut assembly. Place these top parts somewhere safe. - Move the Dust Boot and Spring Seat
The rubber spring seat and dust boot from your old strut are probably in good enough shape to reuse. Simply pull them off the old strut and place them on the new unit. - Replace the Spring (optional)
If you wish to replace the spring as well, uncompress the old spring and put the new spring in the compressor. Be sure not to place the prongs of the compressor on the topmost or bottommost coils - they are necessary for seating the spring when you put together the strut assembly. - Install the New Strut
Put the compressed spring around the strut and place the top parts over the shaft of the strut. At this point it is not necessary to position the spring against the seats. Using either an air wrench or hand tools, tighten the top strut nut of the assembly. Note: Koni struts have locking washers and 22mm nuts instead of the stock 21mm. - Uncompress the Spring
Position the bottom coil of the spring so that it is seated correctly against the strut. The rubber seat is designed so that the spring will only fit one way. Carefully uncompress the spring, making sure that the top coil seats itself properly against the top rubber "doughnut." Before the spring is fully uncompressed, take the time to align the top and bottom pieces as they were before you started. Take the strut assembly out of the compressor and double check your work.
- Place the Strut Assembly in the Wheelwell
This procedure is slightly different depending on which end of the car is raised. The front strut can be positioned simply by lining up the bolts on the mounting plate with the holes on the car's strut tower. The strut can then be twisted around to mate with the steering knuckle. In the rear, you must first position the bottom of the strut between the knuckle and the car body; you may need to swing the rear sway bar out of the way. Then line up the strut mounting bolts with the car and lift the assembly into position. If you have trouble lining up the rear strut assemblies, you may need to compress the spring and manipulate the various parts to correctly align them. - Tighten the Strut Tower Nuts
If you can't easily reach the strut tower nuts (particularly in the rear), these can simply be hand tightened until the car is taken off jackstands. - Insert the Strut-To-Knuckle Bolts
You will probably have to push and pull on the knuckle and/or strut to align the holes. At first, it may seem that the holes on the knuckle will never be able to line up with the holes on the knuckle - it's definitely possible, however, so keep pushing! It is somewhat easier to insert the top holes first in front and the bottom holes first in back - these are generally not elongated, so you have more room for adjustment when you insert the second bolt.
If you do not have air tools available, pound on the bolts with a hammer until the heads are flush against the strut. Use a 21mm socket to tighten the strut-to-knuckle nuts and torque them to 90 ft-lbs.
If you have air tools, simply use an air wrench to tighten the 21mm strut-to-knuckle nuts. The bolt should get drawn towards the strut as the nut is tightened. Torque the nuts to 90 ft-lbs; if necessary, back off the nuts a half turn and retighten for accurate torque. - Replace the Swaybar Endlink Nuts (if working on the rear)
Once both strut assemblies are installed in the rear, swing the endlink back into place and tighten the nut with a 20mm socket. - Replace the Wheels
You will probably not be able to torque down your lug nuts at this point, so just get them hand tight.
Jack up your car and remove the jackstands. Remove any tools from underneath your car and lower the jack slowly.