i haven't done one in my regal yet, but all the ones i have done, you just need to look for the bolts, sometimes they have a hole cut in the inside door skin to get to the bolts, pull the 4 bolts, slide the old one out, put new one in its place, its kinda hard to mess one up, its a pretty straight forward job to do.
its a 30 minute job if its your first time out.