if he installs windshields regularly, he will have the kit. it is widely available. it is just a roll of tar/tape and a couple of spacers. you roll the tape out, place the spacers, set the windshield, and then use the caulk.

at least, that's how i did it. the tape comes in 5/16" and 3/8". i think ours is s'posed to use the 5/16". i used the 3/8" on recommendation from a body man.