Are you going to do this yourself?
I would join "alldata" first...that's what I did, it will tell you everything you need to know. Do you have ESOF? I have the same truck w/4.6v8 and I am rebuilding mine also. Trust me....get a camera and take pictures before you start removing parts.
Remove the extension housing and then the case half (carefully). Take pictures of the shift mechanism and how it sits in the case, it's a strange assembly.
Let me know how it goes.
Email me wsg9(No Email Addresses In Posts!)
good luck