What to do with our live-in Mother-In-Law we don't get along with anymore?

We moved our mother-in-law into our house because she was hurting for money. She pays us some rent - a lot less than she would in her own place. She's been living with us for almost 2 years.

The thing is she's become a nuisance to us by always butting into our affairs and never willing to compromise. It's like walking on eggshells in our own house!

We've confronted her and told her it isn't working out and she agreed but now she is dragging her feet to leave. We just want her to move out as soon as possible because the tension is even worse after this argument.

So how can we push the issue? Any ideas?