Touching the thermal paste ruins the thermal conductivity of it. #1 thing to never do is touch the cpu or heatsink after cleaning it before putting on thermal paste, and obviously never touch the paste either. Same thing would apply to this board and heatsink. The oil in/on your hands totally messes with thermal transfer capabilities.
Doing what
@Airwalker16 said would likely be easiest with least paste use possible. I used an old credit card I cleaned with iso ahead of time to spread it out over my slate 2's for my rspec's.