manual mirrors to power mirrors

I really hate my existing mirror, especially my drivers side one as it won't stay put. I have a switch for power mirrors kicking around, and can get a set of power mirrors off an '89 pretty cheap. I'd like to put these in, but am clueless of how to wire these.
Is there anyone that's done this who can walk me through this? They'll be going into a '90 Pioneer. All help is greatly appreciated.
thx