Oh, so this is slightly more complicated.
Well, you don't know when he's around and his parents aren't so this may end up being a long term operation. Your friend will have to act like he hates you. get in mock fights when you guys are in the same place and the other guy is around. this way he can earn his trust and be able to learn his schedule.
#2,3 your gonna have to be clever about this one give him a reason to go into the backyard at night. this way not only will you be covered by the surrounding area, but it'll also seem less suspicious. like make sure a trash can is full so he has to take out the trash or something. or if he has a dog have him let the dog out. then your friend tackles and the plan continues as planned
-OPTION 2- (just thought this one up, and it's prolly gonna work a lot better)
#1, inside man still used, get them to go into the woods or something (or maybe on the sheep farm

) for a midnight walk or something. maybe even have some girls go along so its like a planned gathering (but remember the more people in on it the better chance you have of being found out)
#2 have a set route for the hike and have your ambush spot set up. this is when the tackle comes into place your inside friend (or friends, because the more people you have, the easier to hold him down) dump the glue and run (including the inside guys, because hes gonna get PISSED)
#3 Once again have a specific route planned out
#4 why in the woods? first of all, it gives you more cover, second since his hair (and maybe his face, shoulders, etc) is all sticky he'll get various things like dirt, twigs, and leaves stuck on him, which will be a pain in the donkey to cut out.
oh, and something to satisfy you more? its gonna be a painful haircut because they have to cut through the glue and other foreign objects
and once again i'm in on it *puts on ski mask and black jumpsuit* Let's rock! *pumps shotgun*