I think he wants a little further explanation then that, Jonas.

He said take the 'transmission off the bell housing'
I am thinking he means he wants to disassemble the tranny itself, not only take if off of the car, so he can get to the internals to see what exactly his problem is.

He seems to have general car knowledge as he has built a car before, I think he just wants a slight walk thru of disassembly to make sure he is doing everything correctly and efficiently.

Which I will leave to you Jonas, As I assume you have more experience and could give a better explaination.