adoubletap Tynan posted a guide to making a DIY cup removal tool using a bit of copper pipe you have hacksawed the end of and splayed slightly to mimic the expensive Park tool above.
Find something like copper plumbing pipe that fits through the head tube / cups - cut it like the picture below and bend the prongs out a bit.
Feed the uncut (thinner) end through the head tube / cup - all the way until the prongs go past the cup and pop out inside just behind the inside lip of the cup.
Get a hammer and then tap the non-pronged end until the cup pops out.
Find something like copper plumbing pipe that fits through the head tube / cups - cut it like the picture below and bend the prongs out a bit.
Feed the uncut (thinner) end through the head tube / cup - all the way until the prongs go past the cup and pop out inside just behind the inside lip of the cup.
Get a hammer and then tap the non-pronged end until the cup pops out.