I'm going through a tough position in my startup where we have to let go of one of our co-founders. It's due to several reasons and the other two co-founders (myself included) have decided that it's the right way to move forward.
What is the normal process in this case? Here are some more details:
If it's a performance-related problem you need to provide at least two warnings before pulling the trigger. You have to give people the opportunity to correct their behavior. If they fail to correct you can fire them and take back their equity, but you will have to pay them back for any cash they invested or let them keep that piece of the equity.
If it's not a performance related problem you can still fire them, but its not fair to take back their equity. Going forward you will have to have a logical way of dilution. As the remaining co-founder's continue to work they should earn additional equity. Use a Grunt Fund to do this.
Here is an article I wrote about termination: http://www.slicingpie.com/the-good-way-to-say-good-bye/
it depend on which country you from Company/firm law is different for all country better consult a lawyer he/she will guide you better regarding all process