he can try to get a used throttle body with the sensor mounted (easiest) or he can get the sensor itself and drill out the rivets on the old one, and then its a matter of finding sheet metal screws to fit the rivet holes.
some1 had a writeup on this pretty recently.

everyone should take note of this case:
MOST jdm engine importers specifically deny responsibility and warrantee on sensors (sometimes EGR and TPS only), because these sensors are very likely to be broken when removing the engine from a vehicle, due to engine lift points and the proximity to the firewall.

~boom