Get a transmission jack, makes life alot easier. If you dont have a body lift on your truck, you will want to unbolt the crossmember first, lower the transmission, then get the top bell housing bolt off FIRST!
As previously mentioned, see the FSM for the general step-by-step procedure. It's a pretty straight forward job.
<img src="/forums/images/graemlins/cheers.gif" alt="" />

I'm between toyotas right now... 3rd Gen 4-runner soon.