A833 shifter plate removal.

Don’t be afraid to shock the bolts. PB blaster on the bolts and then wack the adapter with a wood block and a hammer a bit back and forth. The wood will transmit the energy but not damage the aluminum from the harder hammer head.
Also smack the bolts head on. The shock will break up the corrosion and allow the pb blaster to seep in. I have an old set to socket drivers I use to hit instead of damaging the bolt heads.
Hammer - good!
Wear safety glasses when wacking anything. Lol!