I don't think "easy" is exactly going to be possible. You can do long and relatively painless (that's what I chose) or quick and painful (which I don't recommend). Actually, there are probably lots of ways, but this is what worked for us.
I would begin by starting every night in his bed. Whatever routine works for you, whether that's putting him to sleep in your bed and moving him or doing a routine in his room or whatever. Then, when he wakes in the middle just let him join you. As he gets used to his own bed, he will wake less and less. Also, overtime, he will begin to fall back to sleep in his own bed because he will recognize it as his own bed.
This is what we did with our boys. We decided that we wanted to have an open door policy at night, so we don't turn them down in the middle of the night. We did begin co-sleeping, so when we were ready for a change, we began (almost) every night in their bed.
They both go through phases of coming to us at night, but it's not every night. They also go through phases of sleeping the whole night in their own bed.
Good luck! You'll get there.