We'll be doing the move soon, so no help really, but I'd be interested to see how you go! We also have a cot that the side comes off, but I don't think it will fit a safety rail, so I'll think we'll just go to a big bed. A friend from mother's group has had some success with doing it gradually - so her DD started with day sleeps in there and then when she was sleeping well, the idea was to move her to the bed, but I don't think they've moved her yet. I think we'll just have to go cold turkey because a bed won't fit in with the cot still there! Not sure how we'll go! Maybe I'll do it over xmas when DH is off, so we can both be there to deal with it and not wory about havig to get up for work.