Quick to ship, followed iFixit's instructions and I'm back in business
In photo old fan on left, replacement (used fan) on right. The old fan was slowing down 0-200 rpm when it should have been going 3K rpm. It was making a lot of noise like maybe the bearings were shot.
I purchased a used Right Fan from iFixit for my Mid-2010 MacBook Pro since it still cam with a lifetime warranty and at this point I hope to replace this laptop in the next couple of years. Following their instructions and using a toolset from them made the repair was easy. I printed-out the page showing the screw locations for the laptop bottom plate and I taped the screws to the picture so they were in the correct location.
Print-out the instructions, scotch tape the screws to the picture of the laptop so you don't lose them and they're in the right place according to the photo.
While you've got the laptop open remove both fans, not just the broken one, so you can take out the dust bunnies that have acumulated between the fan and the heatsink.
Make sure you replace the fan wires before reassembly.
Use a Mac OS app called smcFanControl so you can see the speed of your fans. This will help troubleshoot which fan is faulty and if the fix went well.
Note that the Right Fan is the fan on the right side of the laptop when it sitting normally keyboard side up.