As written in DMG P41:
Experience Points: You can give characters XP at the end of every encounter, or wait until they take an extended rest, or wait until the end of the game session. Simply divide the XP total for the encounter by the number of characters present.
Please note, that you can give the XP rewards after the session as well.
About second part of your question - removing XP in general. I am actually doing this in my game too. I like it a lot more, story wise, that PCs grow in strength after reaching certain milestones in my game. [This questions answer explains it in greater detail][1]This questions answer explains it in greater detail
Unrelated - my first answer here. It feels good to be contributing. [1]: Increasing experience gain in session