It depends very much on what your cabinet setup looks like. If you have standard 24" deep cabinets and happen to have am 18" or 24" cabinet next to the sink, it's likely a pretty straightforward job. (Definitely be open to 18" dishwashers if you're modifying existing cabinetry--there are some good ones.) If not, it can get more complicated. For instance, we had 22" deep built-in-place cabinets, and ultimately decided the challenge of trying to modify them for a dishwasher was not worthwhile. If you have a photo, it might be easier to determine who needs to be involved.

A competent handyman-for-hire should be able to handle the cabinetry modification but as noted by the above reply, it depends on the details (and his skills). The machine's drain hose connects to either a port on the disposer (if there is one) or to a T in one of the sink bowl drain lines, which may need to be modified if such doesn't already exist on it.

Depending on Code requirements in your area, there may also be requirements for that receptacle to be used for a Dishwasher.