Can’t get side cover on 833

I know this is a old thread but I need some help. Can you install the forks and side plate with the trans in the car? I replaced my side gasket and got it all back together. But when I installed it the reverse and 1-2 lever will not budge. I think I just got it installed in-correctly. I can pull the trans but for the life of me I don't want too. :(

I've done it so I know it's possible :) Not a lot of room to work next to the tunnel, but there is enough.
I think your diagnosis is correct... don't pull it yet!