1. Remove the panels of the machine.
2. Drain the coffee boiler of the machine.
3. Unplug the coffee boiler element and disconnect the temperature probe wires from inside the orange sleeves.
4. Using a crowbar and a mallet, carefully knock the collar loose (counterclockwise). Once it breaks free you should be able to unthread it with your hand. The coffee boiler is securely mounted to the frame of the machine, you will find the most important part of this step is making sure the crowbar stays in place when striking it as the boiler itself will not move.
5. Remove the silicone plug and pull out the temperature probe. Once the silicone sealant is out, use a 5mm wrench to remove the temperature probe sleeve out of the element.
6. Swap the gasket on the inside of the element, or install a new one if necessary. Reassemble element and tighten down collar, using the crowbar and mallet to make sure it's snug. Reseal the the temperature probe with silicone sealant once the temperature probe sleeve is back in the element.