If you've got a sticky key or large debris stuck under one of your keys, use an Opening Pick or another thin tool to carefully pry up the keys in question.

This can be done by carefully inserting the opening pick into the small gap between the key and the chassis, and gently prying upward.

Don't attempt this on Apple laptops with a “butterfly” keyboard (any 2015+ MacBook or 2016+ MacBook Pro). The butterfly mechanism and the extra-thin key caps are fragile and difficult to remove intact. If you have keyboard problems with an Apple laptop made in 2016 or 2017, you may qualify for the Keyboard Service Program.

Key caps are held on by tiny fragile clips. Be careful as you pry up any keys.