5 - 40 minutes
Right fan blew a bearing, decided to replace left at same time.
Was an easy fix.
Make sure you order the tools you need at the time you order your parts. Don't be trying to make do with something from you tool-box that kind of fits. The tools are cheap, well made, and then you have them for future repairs.
P6 Pentalobe Screwdriver 2009 15" MacBook Pro Battery
TR6 Torx Security Screwdriver
MacBook Pro 15" Late 2008 through Mid 2012 (excluding Mid 2009 2.53 GHz) Left Fan
MacBook Pro 15" Late 2008 through Mid 2012 (excluding Mid 2009 2.53 GHz) Right Fan