Need to replace fans

One of the fans in my laptop is now making a load clicking noise and sometimes has difficulty spinning up on boot. When it struggles like this there is a loud scratching sound coming from the fan. The problem fan is the middle of the 3 fans. I tried blowing air through the fan with an air compressor from both the top and the bottom of the chassis. This did not resolve the issue. I am trying to see if there is a way for me to replace the fan myself, but I have no idea where to source the new one from.