I used part C of Eldar Han's "Filament Guide" from printables and added a bracket to locate the guide using the existing hole at the side of the chassis. So you don't have to have access to the rear of the unit. You will also need a spool holder.
6 to 7 inches of PTFE tubeing
1 M3 *8 screw
1 PC4-M10 Straight Quick Fitting Male