Bricked my Umbrel Pro...help!?!

Noob here. Hi.

So I’ve had my Umbrel Pro for a matter of days and I’ve already bricked the thing…I think. I guess I got carried away with my *arr stack and it completely ran out of disk space and it won’t even boot when I go the terminal route (‘unable to setup system overlay mounts’).

What am I best off doing? I don’t have anything on there that I care about losing too much (a tonne of media files but not the end of the world). Google says I need to flash via USB but I’d rather get help from the community than rely on Google AI tbh…