I did have a refrigeratro leak that damaged the lower 5 inches of one of te kitchen cabinets, I removed the 1/4 in laminate becasu it has some mildew. THe MDF that form the frame has sweled like 3/16 in, can I replace the entire side panel?
If so were do I buy the side panels?

I'm assuming this side is against the frig and not see too much. You can use a piece of 1/4 luan and cabinet refacing material over that.

YouTube - Snyder's Cabinetry Kitchen Cabinet Refacing

YouTube - How to install VENEER

If u bring a sample of finish and size to a kitchen cabinet store, they should be able to get u a pretty good match.

Chuck