The right fan began to "whine" after a 1 inch drop onto a desk. The noise was annoying especially in a quiet room.
The repair was easy. I took my time as not to damage the delicate connectors. In all it took about 25 minutes. I followed the instructions on Ifixit and the repair went fine.
My Mac Book Pro is up and running again although the fan I replaced does make some noise as compared to the Apple OEM left fan. It is not noticeable unless you hold your ear to it. Be careful not to strip the small case screws and be very gentle with the Airport antenna connectors as well as the fan power cable connector.
MacBook Pro 15" Retina (Mid 2012-Early 2013) Right Fan
T5 Torx Screwdriver
P5 Pentalobe Screwdriver Retina MacBook Pro and Air