For starters, try to imagine the Moon as any satellite orbiting Earth (which, in fact, is). It's just a very far and a huge satellite.
What do you do to undock and deorbit from ISS?
Here the only extra thing you have to perform is escaping satellite's gravity pull.
Wondering if anyone knows of any tutorials or resources on how to perform a TEI from Lunar polar orbits? My methods are time/fuel consuming. LTMFD doesn't seem to support TEI from high inclination Lunar orbits.