Reset Z offset in your slicer for the fineliner.
Use the Stl converter in this thing: https://www.thingiverse.com/thing:66115.
This will usually make an STL that is thicker than 1 layer. (1 layer = 1 pass) So either stop the print when it starts doing the second pass or change the Z scaling so that your slicer only produces 1 layer.
I run the prints at 50mm/s.
I keep the Extruder/Hotend setup connected to the printer, just disconnected from the push-rods. Make sure to disable temperature control, if your machine is setup correctly IT WILL NOT EXTRUDE COLD. So you can leave them connected.
3 Tension Springs
3 Lengths of String
1x Stabilo point 88 fineliner. (May work on other pens, but not tested.