I did change my fan according to this solution as it became louder every day.
Getting the fan was a bit of a search - I finally found and ordered it directly from an online shop in China.
When changing the fan the rubbers holding it are quite something to handle - you need a lot of tamper to make that happen.
Being very careful regarding the connector and it’s socket at least to me there was no difference to other connectors compared to eg. a 2013 iMac where I just changed the HDD and the RAM.
So if you are careful and don’t use at lot of force the connector shouldn’t be a problem.
I didn’t have to use a heat gun, the heat the old hard drive of my TC (which I also changed) was quite enough to peel the bottom layer of.
Thanks for this guide!