Modern cabinets are a series of joined boxes with doors. My old cabinets are not boxes at all but a built-in-place run of shelves; how to explain; it is like one huge long box-sort of like one huge long cupboard internally but subdivided on the outside with multiple doors but pots etc can be moved back and forth between "cupboards" by just sliding them from left/behind door one/cupboard one, to the right behind door two/cupboard two. The old doors are very wide and old-fashioned. Can I just replace them with newer, more modern, more narrow doors, or do I have to rip out the entire builder built structure and replace it with separate/joined boxes if I want new doors? The downside to ripping them out is that new boxes which I could afford are all flimsy wood product while the current builder-built arrangement is solid wood. Any advice welcome.