changing coops......help

right now I have a coop that is a 9x10 room off of an old cow barn. It works great. the chickens love it, they can even safely sleep in the rafters that are only about 9 feet off the ground and it square so they have plenty of space. my flock is : 11 chickens, 5 guineas, and 2 ducks. They all go in every night and sleep happily together. I'm want to get some chicks this spring probably 5 or 6 silkies and frizzles ( I dont have either kind in my flock yet) so my problem is space. I have another room in the barn that I can use for a coop. it's 30 x 15. but how can I train them to go into a new coop when the old coop is still going to be there. Any ideas. please help.