Replacing individual keyboard keys

It depends on where you pick your keys from, if you have a spare donor keyboard start trying lifting a couple of keys you are not in need to replace, put the keys and the keyboard under a good light source and better a magnifier too to understand how they work, where the scissor mechanism holds to the keyboard and the top key. Best thing is to lift the key putting some pressure on the edges from bottom and then if needed remove the white scissor mechanism from it metal grips with tweezers. Compare the keys from the two sources before trying to install as not all keyboards have the exact same shape, some are incompatible with each other.