Not entirely sure what “cold pull” means.
You unscrew your extruder, heat the hotend up until you can barely push the plastic across (~170ºC for PLA, ~180°C for ABS), push a bit of it and then pull it out.
Cut the end of the filament and do it again, a few times.










There have been something where some developers left, but I don’t remember it well enough to search for.