Detailed instructions are on the can. You wet the edge of each coat of the blend. You can do the same with a little of the color over reduced but the blending solvent works better.
You can also use a slow reducer for blending. That's how they did it back in the day!
When you've brought your color out into the middle of a panel for blending, dump the paint out of your gun and poor strait slow reducer into the gun, then go over the "blended" area with 1 or 2 LIGHT coats of pure reducer. The reducer will help the paint "melt" or "blend" in. Wait a day and hit the blend area with a buffer and some compound.
Should come out oh soo nice and purrty!