Really all it takes is a 24" wide opening (the width of the vast majority of dishwashers), the electrical supply, hot water supply, and a way to drain (usually to a "pop-out" in the garbage disposer). If countertop is standard height and depth, a dishwasher "should" go in with relative ease. I knew someone who once retrofitted using an 18" wide dishwasher (hard to find but they do exist). It isn't "rocket science" but obviously problems might crop up; I hope you have a relatively easy time of it...and certainly the payoff is worth it!

Good luck!