Forum:Need a save before the final mission

I was trying to make an everyone lives run, but totally forgot to save before the final mission and picked samara to lead the squad by accident. I think that pretty much screws my specialist, Tali, no matter what I do. Can you change the specialist/leaders somehow? The game chapter saved after I picked the two and the last manual save i did was way back in the beginning, I don't really want to redo 10 hours of the same run but so is there a way to either save Tali or get a save file? I'm on PC.