What is the best way to remove a non load bearing wall?
Removing plaster can make tremendous amounts of dust, isolate the area with plastic to cut down on the spread, and get yourself a dust mask and a helmet is a good idea. Cover any cold air returns and heating vents. Once you're prepared, taking plaster walls down is pretty easy, whack it with a hammer to bust a hole, then you can usually get a shovel or pitchfork behind the plaster and it will pull away from the lathe easily as you break the keyway that holds it in. Clean up all the plaster and dust, then go after the lathe with a crowbar and/or hammers; then start cutting the vertical studs with a sawzall.

Double, triple, quadruple check that it's not load-bearing, if the blade is binding when cutting through a stud, there's downward pressure, and even if it's not structurally load bearing, things could've shifted over time above, and taking it out might make things drop or sag.