Hey guys, many thanks for pointing me out to the JST connector - now I know I can get both male and female, even if the female socket is PCB mounted.
The reason for wanting to do this is because my laptop is notorious for bad thermals and opening it up to re-paste the CPU and GPU has become "standard" routine amongst its users. However in order to remove the single piece heatsink, those fan leads must first be unplugged, but they are underneath the motherboard which means the motherboard itself has to come out first. Which is very hard work, a lot of flimsy connectors on board, very delicate, you do not want to be doing this every two months. Which is how long my thermal paste solution seems to have lasted before clearly deteriorating.
Laptop is Alienware 17 R5 with i9-8950HK and GTX 1080.