When removing the drivers side uca the rear bolt cannot be removed and it seems pretty standard to cut it and replace it from the other side. During the process of replacing my uca’s i found that my angle grinder wouldnt fit in the available space to cut the bolt.
I was able to remove that bolt with some finagling and channel locks.
First i removed the front bolt and pull the rear bolt out as far as possible. Then i twisted the uca by pushing the front end inward.
At this point the rear bolt was angled backward so that i could unthread it with some channel locks and it would pass behind the boot.
As a side note, nothing broke, nothing bent and i was able to reuse the bolt.