Just as an FYI: do NOT replace the transmission yourself, unless you really enjoy suffering. It is hell.
That depends on whether you have:
1 - the Right Tools (Transmission Jack (NO, while a normal floor jack will *work,* it really isn't the right tool and will just make it harder. Don't ask me how I know,)
2 - A GOOD workspace. On my dad's F-150, changing that $$#%$#% vacuum modulator would ordinarily have been easy, however, his driveway/carport is actually dirt based covered in wood chips. Definitely NOT a recommended work surface for ANYTHING involving getting under the vehicle. YMMV.)
3 - Patience
4 - A manual / forum post / anything with pictures that SHOW you specifically where the various wire harnesses, tubes, bolts, etc all attach and how they come off, if you're not of the inclination to figure it out on your own. Having a reference can be invaluable and can save you buttloads of time.
5 - Depending on your temperment: An open "hot" "tool throwin' wild profanity" range.