Hey everyone, I was creating my second-ever bowl last night, and ran into this issue:
Attempting to lock the spindle on the red lathe (not sure what its actual name is) does nothing, which makes getting the chuck off extremely difficult. I spent an hour last night trying to save my bowl 
In case anyone else has the same issue, here is how I removed the chuck:
Stick a wrench on the chuck (there’s a flat space where a wrench can fit,) hold the wheel on the left side, and with a downward strike hit the handle of the wrench with a rubber mallet. Doesn’t damage anything, and only took a couple tries.