try heating the heatsink somehow. thats what you get for using that cheap stuff lol.
I don't know what you mean by cheap stuff. Thermal paste is supposed to hardened like cement when cool, the only true way to reactivate thermal paste back to a liquid state is to bake it at 350 degrees, or just simply introduce it to 91% isopropyl alcohol like I did with mine when doing the H105 install, and wipe it away with cotton pads.