Yes, you can,
but I hope you realise you're dealing with liquid metal?
That means if you put too much paste on it, it will run out over the headspreader and onto the motherboard --> short circuit.

Have you watched any youtube videos on how to use it?
https://www.youtube.com/watch

It is important that the surfaces have been cleaned of all residues. The best way is with pure rubbing alcohol (NOT VODKA! xD).