I only started b/w with my LO she was 4 months old and started with the daytime naps. She took all her naps in swing previously. This is what i did...
Put her into bed and pat/ssshhh until dc was asleep (takes forever) and after a few days dc would go to sleep sooner. Then i stopped pat/sshh and just rested my hand on his back, until gradually it wasn't there, but i was still in the room ready for when dc woke to put him back to sleep. Then day by day, i gradually moved further away from his cot and then outside the door.
I would go up and wait outside his door just before 20mins as dc normally stirred around this time and at 45 mins so i could get him off before dc woke up fully.
Obviously some days were harder than others but persistence did overcome resistence. hope this helps. The best tips i can give you are EXPECT resistence and be very, very persistent. It will come, i promise.