The passenger side window on my X5 needs the actuator &/or motor replaced. I have both parts and need some advice on how difficult a job this will be.

I haven't done it but have you read this? http://www.x5world.com/articles/x5/electronics-x5/9463-window-regulator-replacement-bmw-x5.html

the regulator it self is prob f'd but u take 4 T20 torx out of door panel and take it off undo vapor barrier and then take window off track and start undoing the regulator

somewhat easy if you've done something remotely close to it b4

You might want to get a new vapor barrier and a roll of butyl tape, since you'll probably tear the old one.

I havent done it on the X5, but I became so proficient at replacing them on the E46, it would only take about 20-30 mins start to finish. Just be careful with your vapor barrier and make sure that you reinstall the vapor barrier, you rub the glue enough to warm it up and stick.