We've started prepping the forfiveone project car for next years racing season and the first major body modification was adding in some stiffer suspension as well as lowering the smart to reduce drag and get a better balance.
While the there is more detail on the forfiveone blog post here:
http://www.451s.com/profiles/blog/show?id=1912846%3ABlogPost%3A10448
I have posted the below summary of what needs to be done to install new springs into the 451 smart fortwo.
1) Hoist the car up so that all 4 wheels are off the ground.
2) Remove all 4 wheels
3) Remove the front hood flap
4) Remove the top part of the cow, this will require you to remove the side corner triangles and the cow will clip off.
(step #4 is what was the hold up for us as if you don’t remove the top of the cow you will not get at the holes to remove the strut tower nut)
5) Remove the nut from the top of the strut tower, best to use impact wrench as the struts tend to slip.
6) Disconnect the brake line and tire pressure sensor as well as the other suspension bolts.
7) Remove the strut tower and then put the strut tower in a vice to remove the factory springs.
8) Replace the factory springs with the new racing springs, but leave the bump stop in as factory.
9) Do the same for the other side of the front and then reverse the process to reattach the front suspension.
10) The rear springs are a lot easier as you just need to remove the bolt holding the bottom of the rear strut which frees up the springs.
11) Using a crowbar release the pressure on the springs and remove them.
12) Using the crowbar again release pressure and insert the new racing springs.
13) Replace the lower strut tower bolt and then repeat steps 10 – 13 for the other side.
14) Replace the 4 tires and then lower the smart back to the ground, torque up the nuts on the wheels and stand back and admire the results.