Function: They are used to remove factory bushings from above platforms. Also doubles as installation tool for OEM M3 bushings, delrin bushings, or solid aluminum bushings. To remove the factory bushings you will have to drop the subframe but not fully remove it. You need enough access to the top of the bushings to put the washer plate on and thread the nut and locknut onto the threaded rod. For removal of the bushings at the rear of the subframe, you use the tool less the large tanged washer. For bushings in the front of the subframe you use the tanged washer to catch the narrow lip of the subframe holding the bushings. The rear bushings are overall easy. The front bushings without the use of this tool would be extremely difficult as there is no real area to push against the subframe except for the two narrow edges of the subframe exposed thru notches molded into the bushing. Once bushings are removed you can generally install aftermarket split urethane bushing by hand. To installing M3, Delrin, or solid aluminum bushings you will have to fully remove the subframe to allow more room on the top to use the tool to pull the bushings back into place.