I got a little overzealous putting together the caster base and joined these two without slipping the caster underneath is there any way to remove this peg to separate the pieces and do that or am I going to have to print two new bases?
I haven’t got to that step yet, but, in your situation, I would sacrifice the peg. Insert a screw into the top of the peg, and grab it with vise-grips or pliers and pull out the peg?
Each pin location has a hole on the opposite side to knock it out. Just don’t use anything sharp or you will punch through the pin. Use a dowel or something with a blunt edge
This works for all of the pins except the one in the rear caster mount. It does not have that hole because normally the caster is in the way of where the hole would be.