I'm wanting to learn the route and I was wondering how the grate glitch works to get OOB. I haven't actually tested what I think is happening but was wondering if someone could give me a quick explanation.

So checking back on this ? I would really like to do a run of this game but I can't do it until I know how to do the glitches/OOB.

Check out Atair Roses "How to Speedrun Thief" video. He holds the current WR for Any%.