truth be known, I actually agree with the vise grip/duct tape approach and there's probably a host of other good ideas - sometimes you have to improvise.
BTW Mavic North America is headquartered in Haverill, MA but they will only send parts to LBS's ; if he needs the official Mavic tool ( it's just a plastic thingy) it's worth a call through an LBS and maybe they could Fed Ex the tool in time for the weekend.