Have a chat with Alex Whittingham at Bristol GS. He covered my conversion from ATPL(H) to (A).
Off the top of my head it was Op Procedures, P of F Fixed wing, Performance and a 100 Question bridging exam that covered all of the niff-naff that the CAA thought the ATPL(A) didn't cover.
As with everything at Cash Again and Again, you will need to have the ground school approval to sit the final exams.
Enjoy
p.s. The bridging exam was a piece of p**s, use the online question bank from Bristol GS it WILL be the best money you have ever spent.
