My left shift key is semi-stuck in the up position. I have to press down extra hard to get it to work. I suspect there might be a little dirt under the key.

How do I get under an individual key to clean it? I’m assuming the keys don’t pop out like on a desktop’s keyboard (right?), so what to do?

When this happens I generally just blow as hard as I can to the partly stuck key and it’s generally enough to dislodge whatever is stuck there.

To clean keyboards generally, I use Mr Sheen, (a household furniture & surface spray polish), sprayed liberally on the keyboard and then use a blow gun with compressed air from a compressor this forces the polish into the areas between the keys cleaning and taking the dirt & gunge with it as it goes