Angus also taught me a little trick with removing the filament and if you fit a quick release for the filament tube it is even easier .
Unplug the filament tube from the hot end and lift it up to expose a good 75 mm ( 3 inches ) of filament then heat the hot end up to at least 210 c for pla or at least 230c for abs , once hot release the drive roller tension and push the filament down so it oozes out the nozzle then quickly pull up to pull the filament all the way out in one movement .
This will pull the glob of filament in the nozzle out with it and i have yet to have any problems with stuck filament , ideally you will be there when the print finishes or very soon after and this makes removing the filament even easier as everything is still nice and hot .
I once left the filament in the printer for about 6 months and what a pia ! Mistake #2 i call it ! It was a complete strip down of the hot end to get the filament out because it went brittle and as soon as i tried to grab it with anything it would disintegrate leaving me with no other way to get the nozzle or tube clear .