L.R.
Maureen got there before me! She is right on. Taper it off -- if you try to go cold turkey and stick him into bed tonight and say, "Starting tonight you're on your own," things will get worse instantly.
We would sit next to the bed with one hand on our daughter until she was asleep (no more lying down with your child). The after a week or more of that -- and it may take more -- move to sitting near the bed in the dark, no hand, and also no interactions once lights are out; resist any urge to sing to him or talk to him after the bedtime routine is done. Then after days or weeks of that position, tell him you are going to move to the hallway right outside his door; be sure you sit where he can see you through the cracked door. Yes, you stay until he's asleep (I used to read books out there by the dim hallway light). If he gets up to check on you in the hallway, return him to bed by walking him there but do not talk to or engage him or it becomes a game for him.
Gradually, leave your hallway post after 15 minutes each night, whether he's fully asleep or not. Then after a while, leave after 10, then give it time and leave after five minutes. He may have some times when he still gets up during this routine to see if you are there, or to say, "Why did you go away from the hallway?" but say nothing more than, "Night is for sleeping" and walk him firmly back to bed (don't fuss with him--this is not an issue for discipline at all because he is just learning new routines, not being bad or naughty).
This could take a long time -- weeks, maybe months. Be patient with him and don't cave to sleeping with him but do be nearby for enough time that he understands that you are still there even when he does not see you later on.
As for getting up in the night: That may well continue for a while. Again, not a cause for punishment as he is only seeking out comfort and you don't want to give him any message that comfort stops when it's dark; of course you want to end the cycle, so walk him back to his bed and put him in it but with NO talking or interaction (again -- it turns into a game for kids this age if mom or dad talks to them in the night). The very most to say is something like "Night is for sleeping" and that only on the very first time you do it, not on any other times that same night. Turn around and leave as soon as he's lying down again. Every time he gets up, return him in silence and leave. He will learn that there is no positive "reward" if he gets up and comes to you -- he does not get anyone to sleep with him and he also does not get any talk or attention from you; it's just another dull walk back to where he started.
It takes time and a lot of repetition and patience but it does work. If you push too fast, or fuss at him, or try to do it all in a few days, it could backfire and he'll feel less secure that you're going to be there for comfort at night, so go gradually and it will stick. Worked really well with our daughter though we started it younger with her -- since he is over two, he may take longer to get into this routine.