Well if its just one of the hoses probably not, depending on which and access to the offending clip. If it is a balance valve swap, it can (just) be fitted without getting the dash out, but easier if you do I think. In any event a seat out job to let you lie down in the RH footwell anyway! I managed to change one of my hoses in that way. It had been partly chaffed through by the accelerator pedal tail end (LHD car, so next to the tunnel roughly at the valve location)
David