We bought a bunch of zip ties at the local bike store. Remember- they sell bike computers and lots of clueless customers pay them to install them on their bikes- so they HAVE to have zip ties around.

Remember, you will have to recalibrate your wheel circumfrence for the new bike, or it will give wrong mileage readings. You can check it against an old familiar route you used to do on your old bike. Keep resetting the circumf. setting until it matches the old mileage. Or check it against your car odometer and keep adjusting until it matches.