20 - 30 minutes
My Macbook Pro gets a lot of use and the fans were finally reaching a point of strain where they were almost ineffective.
Repair went flawless; the teardown guide was very accurate in stepping me through with disassembly. I didn't run into any issues at all since I have replaced the main board before so I was familiar with the components already.
Be very careful when prying up the keyboard and trackpad panel from the main body so you don't jerk it upward and pull the connector off the main board.
MacBook Pro 15" (Model A1211, A1226, and A1260) Left Fan
MacBook Pro 15" (Model A1211, A1226, and A1260) Right Fan