Forum:Marcus supermarket sweep mission

i like most of you have glitched the armoury, and inturn this has caused the blast door to close and failed the quest. I was wondering is it possible to still do the quest without the use of moding the game? is there another way? like for example joining someone's game that hasnt glitched the armoury and is about to do the quest? if so ... is it possible to join your quest just to finish that mission or will it bugger that players up with the "steel loot" part completeted. Help would be very much appreciated!