There's a bit of work involved -

1) Detatch downpipe from turbo, remove exhaust rubber hangers, drop exhaust

2) Remove driveshaft shield

3) Remove driveshaft, support each segment so you don't bend the CV joint more than it bends while attached to the car, transmission and differential

4) Finally get to the transmission. Mind the engine rpm sensor behind the oil filter housing. There are 6 bolts that take a 5mm or 6mm hex bit holding the torque converter to the flex plate. As you turn the engine CW only(!) the bolts will appear in pairs in the oval port at the bottom front of the bell housing. Might be worth marking the alignment of the torque converter and flex plate. When the torque converter is free, push it back into the transmission. There's provision for a locking key on the driver side of the bell housing so the torque converter doesn't fall out if you tilt the bell housing down. You can probably find a bolt or something to use instead of the key. Some bell housing bolts are easier to reach from above.

Aside from seals, there's also the B2 piston, K1 spring kit and a shift improving spring kit available. These things aren't difficult to replace with the transmission in place but maybe you don't like working on your back with ATF dripping on your face.

Sixto
87 300D