I'm sorry to say that I think this is harder to do than you imagine. There are three types of appliance - free-standing, built-under and built-in. I think you are trying to convert a free-standing to a built-in. Manufacturers make built-in units to specific dimensions so they fit they 600mm wide std door width. They charge a premium for the privilege, but it includes adjustable legs to shift the height of the unit up/down to fit the kitchen units around it, and has an air vent at the bottom to allow air in and under the unit to help cool the condenser coils at the back of the unit - this has to fit with the kick-board that runs along the bottom of a run of kitchen units. Built-under units are intended to fit into a run of kitchen units but they retain the original (white) front door of the appliance. Having converted a free-standing dishwasher to fit as a built-under unit (including lifting it off the floor and making the kick-board look right underneath) I would never attempt it again - too much fiddly fitting work to make it look right. Sorry, but you may as well bite the bullet and change the fridge.