There's no easy way that I know of BUT you can import another copy of the layered file (PSD?) with "retain layer size" selected and then replace all of the layers in your original comp manually. You'll have to select each layer in the original comp and then go to the project panel and find the corresponding layer in the new comp's layers folder and then Alt+drag and drop the new layer onto the old layer in the timeline or the comp viewer window to replace it(shortcut is Ctrl/Cmd + Alt/Opt + /). When you do this the layer will jump to a new position since it's not the same size as the original layer so you'll then have to open up the newly imported composition, select the corresponding layer in there, copy its position and then paste it onto the layer in the original comp. It works, but it's a little tedious. HTH
Erik Waluska
EAWmedia
