Pull off: This is just the reverse of a hammer on. Play a note on the 10th fret with your ring finger while you index finger is already on the 8th fret. Then just pull your ring finger off the string, so you can hear the note on the 8th fret without having picked the string
Palm muting: Place you're palm of your picking hand on the strings in proximity to the bridge. The distance at wich you place your palm, and the pressure you apply determine the sound of the palm muted notes you play.
Hope that helps.
Greetz, TK