My friend gave me his old PC so I can upgrade it for him,everything was full of dust and dirty,so we cleaned almost everything but the heat sink was full of dust,we tried to get it off the processor but it somehow got stuck so we pulled a bit harder and when we pulled it out the processor was attached to it,the termal paste hasnt been changed for 15-20 years so it was so hard it pulled the processor,the processor is not damaged,can anybody tell me how to get the processor off the heat sink??