Do not be in a rush make sure that the glue has set. Remove the weights and carefully remove the jigs from the ribs by wiggling them careful back and forward. If a bit of roof comes off or has not glued properly do not worry as a small dab of thick superglue and a clothes peg will normally fix it.
Once the jigs have been removed trial fit the roof. It probably won’t fit the first time, this is to be expected. Using a small piece of sand paper relief the ends of the ribs that are tight. With a little careful sanding the roof will fit. Don’t over sand as the roof will rattle or fall out. In the example shown the central compartment ribs have been left out.