It is possible to remove the motherboard whilst keeping the daughterboard in its place. However the flex connector of the daughterboard sits on the backside of the motherboard and it's a bit of a fumbling to disconnect it while you're holding the motherboard in your hand.

In case you're planning to remove the motherboard without the daughterboard take especially care not to damage any surrounding components whilst disconnecting the flex cable.

Use the pointed end of a spudger to pry up the motherboard until you can get a good grip.

The motherboard sits loosely on the mid frame so there are different positions to place the spudger and to pry it up. Avoid to damage any surrounding components.