Basically you need a file searching app and a portable router. The app I used was ES File Explorer (other names are AirDroid and File Expert). The portable router I used was a P2R-100 (other names are hoo-too and TP-link). The portable routers are about $35 if they have a charger or a little less without and the apps are a couple dollars.
Anyway, insert the USB into the router and connect to the router's wifi. On ESFE you have to type the address of the router (menu>new>server) and then it will show up on the 'share' menu where you can access files.

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