I just bolted up my ’64 engine in my early Corvair. I noticed that the forward transmission mount on the driver side appears to be bad.

So,,, it looks like I will be replacing both mounts. (These are the pair of transmission mounts that attach to the bracket behind the transmission that hold the front of the engine up.) These mounts look tricky to remove since the forward bolts on them are in extremely tight to the body panel. I would like to do this without lowering the suspension sub frame or removing the engine again. I am wondering if anyone has any tricks up their sleeve on how to do this?
One thought I had would be to lower the front of the engine, say 4 to 5 inches, and remove the back seat and cut a small hole so I can get a socket in there. I may have clearance on the passenger side to get a wrench in that I would bend at 90 degrees, but the driver side is very close and I may need a hole cut to get access to the top of the bolt.
I would be interested in any suggestions. Thanks.