Locate the CPU socket, located near the middle of where the heatsink was, using a flathead screwdriver rotate the arrow to the unlock position with the corresponding unlocked padlock icon.

This is the time to use Q-tips to clear any thermal compound (thermal paste) on the processor.

Lift up the processor from the edges.

Do not touch the processor by the gold pins, and do not touch the die, touching either could cause potentially unrepairable damage.