Looked into this a couple of years ago.
Unless your mil type is a twin easa type e.g Bell 212/412 you can't open your ir civil licence on mil type.
First you need to do the 14 theory exams. This takes a while, read months-years.
Then you have to do a type rating, cpl test and ir practical in an easa type.
Expect £20-30k for the lot.
Might change soon though, I was told that in 2015 though, glad I didn't wait.