shifting audio keyframes in premiere pro

[flextone]

Hi, I have edited around 1hrs length of footage and then mixed about 7 layers of surround sound mix using the audio mixer in premiere. However now i need to cut this down to 45mins, is there a way of doing this without mixing the surround effects again, i.e. sync the audio mixing "e.g. fade from left to right track", as otherwise I would have to go through each audio track after editing and redo it all!

thanks for any help
flextone
reefclub