I had a failed print. And then I damaged the hot end wiring pulling this ball of filament off. And damaged the extruder parts with the heat gun trying to get the ball off. I have a mk3 to mk3s upgrade I’ve been putting off installing. So I am working on fixing it up on this rainy day. I got a new hot end from spool3d here in town. Lots and lots of steps maybe 100 in the documentation. The instructions are very good with detailed pictures.