I'm not sure how to remove an old Thermaltake CPU cooler

Solution
this is a old intel cpu cooler so unscrew the fan then use a flat screw driver to press the flat bar in the middle of the fin then unclip both side of it keeping the pressure on the flat bar until both clip are off the motherboard .
this is a old intel cpu cooler so unscrew the fan then use a flat screw driver to press the flat bar in the middle of the fin then unclip both side of it keeping the pressure on the flat bar until both clip are off the motherboard .
 
Solution
I got the fan off and the metal bracket (probably could've left that on), but I can only get one side loose (the side closest to the RAM).
Is there something I'm doing wrong? Should I be using a lot of force?