I got a cpu cooler (Hyper 212 Evo) and i got an Asus M5A99FX PRO R2 motherboard. To install the cooler it seems i have to replace the stock cpu backplate with the backplate that comes with the cooler. However when i try to unscrew the backplate the screws wont budge ONE BIT, and im not weak. Is it supposed to come off at all? Am i doing this correctly? Any tips to loosen the screws?