There will be a lever on the CPU socket, called a ZIF lever (Zero Insertion Force). It is so you don't have to pry the CPU.
To remove the CPU, take off the heatsink/fan, then lift the ZIF lever. The cpu should come out.
TO put the CPU in (assuming it is compatible with the other motherboard), lift up the ZIF, align the CPU pins with the holes, put in the CPU (no force needed, it should drop in), then put down the ZIF, and put on the heatsink/fan (with Thermal Paste, just a tiny drop should cover the CPU, make sure to wipe the CPU).