Replaced mine the other day and also did it with out removing the spring as was suggested here. Figured out that no way was the bolt going to come out from the top under the spring perch. I tried for about an hour and figured out that it couldnt be removed with out removing the spring.

So I got to thinking(dangerous on my part) and decided that if Ive gone this far that the only way to remove the bolt was to cut it off. Knowing that it is hardened steel... cutting it with a hacksaw wouldnt work... so I got out the torch and cut it.

Had to put it back together with the bolt upside down as there was no way it was going back in from the top. Im sure MB didnt want it installed that way for if the nut came off from the top the bolt would drop thru...but I will just keep an eye on it in the future to make sure nothing comes loose.

Had to use a bottle jack on an angle up against the lower control arm to move the lower arm slightly forward for the bushings and bolt to line up. I guess the design of the lower control arm gets pushed back into the rod if the bushing is removed. Better that way than the opposite as it probably would have popped the spring out if you arent careful as the lower arm has only one pivot point...and is subject to side loads that could pop the spring when the bushing and bolt are removed.