>and yes that is the plan, limiting my time around them and basically avoiding them till they get the hint.

They won't get the hint, all it will do is make you seem more absent, slowly increasing the distance between you two, cutting them off slowly or frustrating them to the point where they cut you off. This method never works and might achieve something you don't want.

Before you do anything in particular, ask yourself: Does your friend even have anyone else to talk to about the issue at hand? Why is this so important to them? If you want someone to back off in terms of complaining it's often a good idea to look at the reason why they're complaining to you about something or someone.