Be very careful, you're about to work with the HotEnd. Be careful not to burn yourself.

Take your HotEnd sock off.

Once you're sure that the printer is in working order, heat your HotEnd up to around 280°C. On the LCD Screen this would be: Menu → Control → Temperature → Nozzle → Set to 280 (or as high as it goes if it's capped below that)

Tighten the nozzle with a wrench. It doesn't need to be incredibly tight, one finger on the wrench is all you need.

Load some filament in manually by pushing back the idler lever and inserting it until it comes out of the nozzle. Make sure no filament leaks from the top of the nozzle.

Cool down the printer.