I need help on LEGO Star Wars II : The Original Trilogy?

I'm stuck on the 1st level! I can't get ped the part when your playing as, Captain Antilles and Princess Leia and you walk into the white room and there are 4 levers, but Darth Vader comes in and 2 Troopers and they shoot at you, I tried to pull all 4 levers and it didn't work, then I got my mom to come help me, we double-teamed the levers and we pulled them all down before a lever clicked back up again, that didn't work either, they rose up again! I search cheatcodes.com, cheatplanet.com, ign.com, mycheats.com, stuckgamer.com ect. But I couldn't find anything! So I need a really good answer because I really Love this game! :)