JABI is absolutely right, it's not something you do overnight. It's a lenghty and complex task. You'll find details
here ,it's a PDF-file containing JAR-FCL 1, Section 1. You'll want to go to page 1-A-8, para 1.055, for starters. It's not long, but all the Annexes to 1.055
are . You'll also want to read the advisory material in FCL 1 Section 2 concerning this, unfortunately, JAA doesen't put Section 2 on their website.
You'll also have to be prepared to pay all associated expenses to the NCAA handling the approval application.
Enjoy, & good luck

, it can be done, several others have.
cheers,