Hi there, can anybody kindly tell me how to open the doors of the pmdg 747-400, thanks.

Press the ALT button go over to your PMDG tab go to GENERAL and then KEYBOARD COMMANDS in the COMMAND CATEGORY select DOORS 747 then assign a key stroke to the doors you want to open. Just make sure you do not overwrite a key you may already use. Hope this helps enjoy this incredible plane.