Go to Settings, System, Storage; enable "Storage Sense", and click on "Change where new content is saved". From there, move everything to your USB stick (and make sure it's fast and small so you don't yank it off the laptop).
Go to Settings, System, Storage; enable "Storage Sense", and click on "Change where new content is saved". From there, move everything to your USB stick (and make sure it's fast and small so you don't yank it off the laptop).