2000 audi A4 1.8T quattro avant aux cooling fan

The aux fan is making a racket when activated by turning on the a/c(fan closest to the air filter). It looks like the fan is loose on the fan motor shaft. Is it difficult to remove the fan? Is there any problem with disconnecting the plug to disable it? I checked online for a replacement and it looks like a nut holds on the fan blades to the motor shaft. Please advise on removal. I would hate to have to replace this $200 fan if it is something easy to fix.