If they are rollers you can "settle" them in 2 weeks by putting them in an aviary so that they can see the surroundings. If you don't have aviary, then hopefully you can put some settling cage where you can put the birds there on a landing board. You probably can trap train them after couple of days of having them. It is easy to lose rollers because they don't have much homing ability at all though. Certainly only release them only hungry so that when you want them to go inside the loft you can either whistle, shake can or depending on how you train them to respond to you during trap training.