Key mechanism is very similar to 12" Retinas, due to the butterfly mechanism. Usually, the keys are held to the mechanism in the 4 corners of the key, use some tweezers to unclip it. Bare in mind however, it can be very easy to damage the holding clips on the key cap or the mechanism itself (even if you just pull the key off, have this happen randomly on the older models sometimes), and there are no key caps or keyboards available on this model yet. If you break it, you are stuck without a key, so I would recommend doing it once keyboards and keys are available (probably 2-3 months time).
See step 21 here for a picture of the key mechanism (should be no different for touch bar version) MacBook Pro 13" Function Keys Late 2016 Teardown