I want to convert from a rented 500gallon propane tank to my OWN 100g tank. what do I need?

The propane company I have been using for 18 years, has become HORRIBLE. and I cannot stress "HORRIBLE" enough. I currently have a rented 500g tank that is hooked to my home (for the water heater, kitchen stove, and propane gas stove for heating part of my home). I want to fire my propane company and use the 100g propane tank that I have. What do I need to hook the smalled tank up? I know I'll need a regulator, but what else? Thank you