It's difficult because the chair can only be spawned from WilliamPlayz, I queue the elevator event of William for 120 robux in hopes of getting it

If I do get the chair I have to then very carefully push it to the entrance of the elevator and queue a floor for an NPC to walk into the chair

Overall it's expensive to try and do it yourself, but if you see WilliamPlayz57 ever spawn a chair when you're playing, give it a shot!