Sorry, I didn't read your first post. Since you already hold an ATP no written is required. Training centers that use sims for types operate under Part 142 of the regs and have to do a training program that is on their approved syllabus. Most of them as Mungo says have a "short course" for people with time on the aircraft. I work part time for a 142 school and we normally put someone like you through through our "Upgrade" class. Off the top of my head I can't recall, 4 days of class and 3 sims or 3 days and 4 sims. Obviously you don't need a complete Initial class.
Doing the check ride in the plane falls under Part 91. It used to be, prior to 2000, you could just show up with a completed app minus the sign off and go fly. The idea was, you're an ATP, you know if you're ready or not. Sometime in the late 90s the FAA added the requirement for an instructor's sign off for a type and as I said I don't think any CFIs will put their name on the the app without flying with you some.
All the FAA guidance is found in a document called FSIMS available on line. Click the "contents" "airman certification" and Chapter 2 "Part 61 certification" and section 19, "conduct a type rating certification." Sorry, it won't copy for some reason.