Based on the video from tokopedia, it seems like you might just need a depinning tool. But these look extremely cheap, so buy a spare and pull it apart to figure it out. I doubt you can replace just the gasket and you will probably need to replace the whole connector.

If you want a fan, why not buy a whole assembled fan? There are 10mm and 15mm fans available.

https://www.digikey.com/en/products/detail/sunon-fans/UF3A3-700TC/9805482?utm_adgroup=&utm_source=google&utm_medium=cpc&utm_campaign=PMax Shopping_Product_Medium ROAS Categories&utm_term=&utm_content=&utm_id=go_cmp-20223376311_adg-_ad-__dev-m_ext-_prd-9805482_sig-CjwKCAiA9dGqBhAqEiwAmRpTC2Ttw0neG0EI6dWMknvt-j5AM1hHRZyi0VnILDQ7MoZNEe34IoIR7BoC3SYQAvD_BwE&gad_source=1&gclid=CjwKCAiA9dGqBhAqEiwAmRpTC2Ttw0neG0EI6dWMknvt-j5AM1hHRZyi0VnILDQ7MoZNEe34IoIR7BoC3SYQAvD_BwE