I'm going to kick an old lady off a machine at the gym
Why would you kick her off the machine?
Because the way she is using it is pissing me off.
I can tell you're frustrated by the situation, but forcing her to get off the equipment will just make things uncomfortable for everyone. If she is using it improperly, instead you should explain to her the correct way to use it so she can exercise more safely.
No, she is wasting the equipment by doing it wrong. There are people here who know how to use it who need it!
She has just as much a right to use the machine as anyone. Unless she is endangering other people in how she is acting, there's no reason she should be removed. If this is such an issue, bring it up to a staff member at the gym and they can help resolve it.