How do i train my kids to sleep in their beds?

I have twins. I really need to train them to sleep in their own beds. they are a little over a year and were born prematurely. came home on breathing machines and heart monitors so for basically the first year of their life they slept with me. So now that they are getting bigger and off all their machines and seem to be going in the right direction health wise, how do i go about putting them to sleep in their own beds. I am a single mom and have not much self control to sit while they cry so it is going to be really hard for me, but I know it will be for the best and will make everyone happier and sleep better once I know they are safely soundly asleep in their beds.