How to tell a Realtor you are going to go with someone else?

[Mark Mo]

Hi BP, 

So I've decided that I'll be going with a different Realtor. .. My questions is, how do I professionally and politely let my current realtor know that I'll no longer be working with them. They have been great and have shown me many properties, but when it came down to it, I really did not feel like they had my best interest at heart. We are not in contract.

If you have any experience with this, please comment below. I would really appreciate it.