Here’s a Kegerator conversion of a Danby fridge from Costco. It fits 2 ball lock kegs (tall ones only).
Step 1. Remove the top
There will be a piece of foam in there. Throw it away.
Step 2. Add a piece of 1/4 inch MDF or plywood. This will help make the tower more stable.
Step 3. Measure from the inside to the refrigeration unit in the back of the fridge and mark it on the top.