How to fire a horrible employee in California?

We have a horrible employee that we do not want to fire, we are afraid she might file a lawsuit or file for ui. The employee comes in 2 out of 4 days or misses a week at a time. She makes sure that she calls in, but gives horrible excuses. She has pulled every excuse. She constantly comes into work high, looks on CL for other jobs, does not take direction, leaves early and pays herself for days she has not worked...the list goes on. I am not the manager, but an employee who has been there for 10 years. I am completely appalled by this woman and want to see her out of our office. Does anyone know the legalities involved in such a case?