Too much to alter ---- you will probably need new case as well.
Think about replacement of the entire box.
Novatech offer a range of boxes only, or their Blueprint service where you choose the components online and modify or scrap your design as you please. Clever interaction takes care of incompatibility and updates the cost as you go.
I mention Novatech because I have used them but there are others, and it is no cheaper if you build or rebuild yourself.