Not really sure you can repair that. Depending on the motherboard you can plug it into any fan header or molex adapter from the PSU and disable the CPU fan error in BIOS.
Molex will make it run full speed all the time and might be loud.
then your options are very limited. How damaged is it ? I did re-solder connectors that ripped cleanly, but it all depends on how badly its broken.
do you have any other fans in system ? Maybe you can get away with the splitter ?