While not for this model Ive done this a bit on thinkpads; and in a past life was a apple certified technician who worked on a few apple laptops.
I dont know your comfort level with opening up a laptop/computer so forgive me if some this is old hat , but usual static wrist strap warnings apply ; if you dont have or don’t plan to use an anti-static wrist strap you sould ground yourself beforehand to eliminate static electricity. Before opening a machine is always a good idea to do this. Mostly for your laptop’s safety. Also make sure to follow this take apart’s instructions about disconnecting the power and battery before opening the laptop.
If you have a step by step take apart guide you should be good. Have a system for keeping track of the screws and go slow if this is your first time diving this deep into your laptop internals.
There ought to be a layer of thermal paste between the fan/heatsink combo and the CPU. You might be able to order the fan & coper bits with thermal paste pre applied. Ive found lots of those lying around on ebay for various thinkpads before. That sort of thing make its breaze.
Just be careful not to touch the thermal paste with your dirty human flesh hands. If you do your supposed to clean the thermal paste off with rubbing alcohol and reapply the thermal paste. It’s not toxic, but the oils of your skin can muck with the effectiveness of the thermal paste. Ive been a dufus more than once and mucked it up. Thermal paste is cheap and easy to apply.
I do advise having some thermal paste around in case you need to reapply or in case you cant get the new fan running and want to return to the old fan for a bit and regroup.
Im kind of fond of recommending Noctua NT-H1 thermal paste as it’s cheap, easily found online, very highly rated in terms of thermal transfer, and it is also not conductive. If you get a little sloppy with conductive thermal paste you can accidentally bridge circuits in your laptop which ought not be connected. Zero risk of that with non conductive paste no matter how sloppy you get.