Take the hub stacks off a grind machine and put them on a champions superstar?
yes just remove stacks,oring,bearing from grind machine and take the nubs from the supertar and put the bearing,oring, then stacks on it.
the bearing in the grind machines hub stacks are stuck in the stacks.
Happens with all hubstacks. Take a pencil or somthing similar and press on the bearing through the hole in the top of the hubstack. If that doesnt work, try freezing the stack then trying again.
all else fail just use light force with some pliers or even your teeth
And your dentist will love you for it.
Or put the loop of string(the one you put on your middle finger) insert it underneath and pull(worked for my old skyline)