Replacing door handle, 2002 Impreza?

The driver's door handle needs to be replaced on a new-to-me 2002 Impreza. I could take it to the dealership where I bought it (at no cost, but nearly 100 miles away) but my son thinks he can do it; he's done a LOT of work on various Hondas and currently has a Subaru, too.

Is there anything to be especially careful with if we go the DIY route? Any risk of screwing up keyless entry or other electronics?

The lock still works and is attached but the handle has pulled away from the body of the car.

Thanks for any help you can offer, and if anyone has access to an emailable repair manual which shows how to do this, that would be great!