How to make manual liftgate a power liftgate?

I have a 2011 Chevy Traverse LS FWD and it doesn't have the option of a power liftgate. I would really like to have one I done some research and I can get all parts modules, motors that is required to make my manual liftgate a power liftgate. I'm just wondering how hard and if there would be a lot of modifying to make this possible and would I have to get a body shop or could a regular alarm system installers do the job? Also if you could list all materials required to make this possible.