board respin required...either position the button so you squeeze the enclosure to press the button (it flexes a bit), or drill a small hole (use a jig to get the drill bit in the right location
enclosure co's will also customize/drill holes for you but its probably easier for you to just diy!
Oh, nice solution. I thought he'd have to order USB device enclosures from China, but these are from Bud Industries in Ohio, the classic maker of electronic enclosures for 80 years, and orderable from Digi-Key. (That means the parts will be good quality and they will show up on time.) Get a custom sticker printed, and you'll have a good MVP.