The installation took about 15 minutes with the right tools and its all about location anyway. Take a careful look around and about the motor location and protect your hands with a good pair of gloves since the abundance of sharp edges underneath a fridge freeze should come as no surprise. It is hardly a well engineered space you will be working in. Check out the old motor or component once you have removed it, check the screws of bolts with which you will be installing the new part, for example, the bolts used for this fan motor are self threading, so the first bite into the non-threaded plastic housing might take you by surprise since alignment of screws might be a problem. The fan that attaches to the motor haft isn't keyed, or even structured in any way, it just plain pushes onto the round motor shaft with brute force, so attach the fan to the shaft before you mount the motor-fan comb.
Good luck with you own DIY project, since you can save yourself some serious coin with the right attitude and a new part.