OK Newbie to double extruder J1s and Snapmaker Luban 4.10.2. Have previously only used 5mpro with one extruder. How do I turn off the right extruder if my model only needs one? Downloaded the pencil cup 3vd from thingi and J1 wants to use both extruders. Also, is there a way to reduce the thickness of a skirt or brim?