Apply a small drop of liquid metal to the heatsink (not the APU)—about the size of a small matchstick head.

If your liquid metal syringe has multiple applicator heads, use the one with a small, needle-like tip.

Use the spreader that came with your liquid metal or a new cotton swab to lightly push down on and evenly spread the liquid metal across the entire surface.

If there's excess liquid metal anywhere, use the syringe to suck it back up.