Shift kits are relatively easy. Anything requireing pulling the front pump will need a slide hammer (preferably two but I did it with one). Deeper in there are a few things that are best to remove with drivers made to fit. That's where it can be a real pain. My impression is most folks either leave those parts or (like I did) find someone who has the tools.

I made a stand out of angle iron to hold the case while working on it. Not critical, but something to consider.

Swapping guts may or may not make sense - depends on the years and exactly which guts. The Monroe book on 727 transmissions covers the year to year variations etc. Well worth buying for someone considering swapping parts.