Just start going at it with whatever tools you have. I can't think of any common tools that would push the pin out except a chain tool, but you could try:
- Shove a screwdriver in one of the larger holes and get the plate to pop off
- Cut through it with a hacksaw
- Go to your local bike shop and ask to borrow their chain tool
However: You'll probably need a chain tool anyway, to take the extra links out of your new chain.
- Shove a screwdriver in one of the larger holes and get the plate to pop off
- Cut through it with a hacksaw
- Go to your local bike shop and ask to borrow their chain tool
However: You'll probably need a chain tool anyway, to take the extra links out of your new chain.