At the end, before you pneumo tube into the level 9 room, be ready, as you gotta immediately get as many light bulbs as you can, since that's when he descends from the elevator. Once you fill your inventory with bulbs (and the level 9 keycard), you leave using the keycard, and put the bulbs into the sockets by the giant grinder. (make sure the platform is extended too, by pressing the button in the adjacent room) Once you've filled just about every socket (I don't think it matters if you get them all or not, only enough to lure him over the grinder) you'll want to get to one of the safe spots (the best one would be that slightly lower platform past the grinder) and wait for adam to walk out of sight, then shoot a portal into that room with the button and wait for adam to walk over the grinder, where you then push the button to drop him in. Of course him being him, will not take him out completely, but he is slower now. Now you gotta make your way to the giant hydraulic press. (It should be out the left side of the button room, and take another left once out. Once you're there, simply sit yourself inside of it and have a portal ready behind it for when adam gets there (The sides of the hydraulic press are bars, so you can just shoot through them.) When adam eventually gets there and stops at the base of the press to grunt at you, wait for him to perform a lunge (which is about a second after he grunts at you, or if you're observant, watch for his animation change, that's when you portal out and hit the big green button to start the press. Congratulations, you have done the do :V

or you could alternatively grab a broken supervisor head from the trash chute above the grinder and use it to escape and spare ADAM

Originally posted by Sargent Syrup:

or you could alternatively grab a broken supervisor head from the trash chute above the grinder and use it to escape and spare ADAM

do u need to get him spawned in or can u just grab one

You can grab one before he spawns, but you need him to bring down the elevator.

I highly recommend beating him the regular way though, in fact, i'd go as far as to say doing it this way is practically cheating the game and yourself out of an excellent moment.