K.i.s.s. Just like you would if your were doing a cam install from the fender area..drop one side of the subframe slightly..just enough where the bolts are still threaded in and the subframe is still holding on..stick a jack as well as jack stands underneath to prevent it from falling out..then with a jack underneath the otherside jack that side of the subframe up then completely remove the 2 bolts..replace the bushings..jack it up thread the bolts in.leave the jack and then vice versa and do it for the other side? Does that make sense?