The cord comes off the top. It passes through a hole drilled in the cabinet bottom plate, using the included template for location.
It is a little tedious to install the MW because of the weight. It is easier if it can be installed before the range goes in, but usally that doesn't happen. You have to muscle the MW with the front tipped down at a 45º angle, catch the hook at the bottom of the mounting bracket, then tip the MW up. Someone has to hold it in place while the bolts are installed down through the cabinet into the top of the MW.