Remixing InternalError33's excellent guide since I couldn't find PTFE tubing to fit that one. The bracket holders are directly from InternalError33's post.
I feed filament directly from a Sunlu dryer that sits next to my Mk3s+ (see photos). This routes filament from the dryer through ¼" OD PTFE tubing (available from McMaster Carr here) to approximately the same point it would exit the default Prusa spool holder.
It moves the filament through approximately the same radius as the inner diameter of a filament spool to avoid overly stressing it.
I printed mine in PLA since I only ever really print in PLA. Recommend a different material if you print higher temperature materials. PTFE tube not included.
Questions, comments, suggestions, corrections are welcome!
The author remixed this model.