Crosspost from SDA:
Chamber 0: wallclimb radio launch, abh to elevator
Chamber 1: acquire orange portalgun, clipping glitch out, acquire blue portal gun, clipping/edge glitch out again, to fizzler, into elevator
Chamber 2+3 get skipped
Chamber 4: abh, portal on the right of the entrance (players left), fall into pit, clipping glitch out, walk onto the observation room, shoot portal to the trigger inside the hallway at the very end, pqr, into elevator
Chambers 5-7 get skipped
Chamber 8: hit 1 portal through the seam above the door, wait. shoot 2nd portal to the upper step, jump onto the 2nd step, shoot portal behind the right turret to the very top of the wall, either clipping glitch out or edge glitch in a way that lets you shoot a portal on top of the mario warp zone, pqr/pbf in, go into tube “level 6”
Chamber 9-15 get skipped lol
Chamber 16: Portal bump (e.g. 1. blue, 2.orange) at the top of the right wall, go OoB, shoot blue below the button, portal stand. shoot blue onto the fizzler and move back in time to do a pqr onto the button (triggers the elevator doors), move through a new orange portal for a pdr (emancipacion field reentry)
Chamber 17 gets skipped
Chamber 18: blue portal to the very right end of the hallway, orange infront of yourself, go through, abh, portal bump through the door, abh along the right side of the glass channel, around the corner. hit the wall that you can see in the top of the hole in the ceiling, clipping glitch out (look to the right) hit the very end of the level, pqr in, skipping the portal gun removal trigger.
Ending: cliping glitch out, portal on top of the core holding room, from there shoot below the final room before the catwalk to the glados activation room (you can use that shot to pbf into the core room) start the core release, pqr into the other room (portal too the floor, where the core falls), open the door, setup the edge glitch, get the core, upper edge glitch using the core, fall into glados room (stay ontop of the tv), peek a portal below glados, other portal below yourself, drop the core into there. game ends here.
Ive done a video of it (route has changed a lot, but the necessary parts are in there):
New route for 8:
(can still be optimised)