I just finished a clutch/rms/tcase rebuild. It’s a lot but not $4k a lot. You’ll need a trans jack, lots of brake cleaner, and a hydraulic press with some special bearing pullers to do the bearing work inside the tcase. If yours is an 85-87, you can bolt the trans mount directly to the jack which avoids the balancing act I had to do on my 84.
I followed a combo of the OTRAMM and Valley Hybrids YouTube videos, although both of those are for vacuum tcase on a 62 with and H55 attached, but almost all details are the same.