After scraping off the TIM, polish the base of the heatsink with a towel and a little toothpaste. Rinse off. (Not the fan you dummy!)
Then squeeze just a little of the silver onto the core. Don't squeeze too hard, or a huge jet will fly out and waste all of it. It happens. Spread it thin over the core with a clean credit card. You might want to do the same with the heatsink.