S17's and such have a nice little extra feature: They have that copper top that has solder on it, remember?

Then take out the board and put the heat sink on. Remember, no pre-heat, put a bit of flux on the center of the heat sink, line up the sink perfectly (the flux will hold it in place) then low flow heat from the air tool to secure the heat sink again.

I'm a bit confused by this. If you put on a new chip and clean the solder off from the bottom of the removed heat sink. You don't need solder paste and just throw the heat sink on with a little tacky flux because that copper top has solder in it?