As you 3D print more and more frequently, clogged or partially blocked nozzles actually get rarer as you learn how to avoid them. But if you do manage to get yourself a blocked nozzle, here’s how to fix it!
https://www.youtube.com/watch?v=g8uvh6kvr54&feature=youtu.be
Concise awesome video.
My CraftBot extruder is now clogged big time. Been using my CraftBot since Dec 2014. Not printing regularly though.
My nozzle has clogged a few times (in part of me not taking good care of my printer; leaving filament in extruder when printer is off & when printer is On, leaving the head heated for long time before printing).
My Friend helped me to clear the nozzle recently once. Previous few times i managed to raise temp up to 260 deg. C & pushed filament through.
Now despite raising temp to 260, can’t push filament through, more than a 3/4 thumb length.
Appreciate some help. Thank you
Вовремя 
Managed to unclog it. Will post details later.
@Thomas_Sanladerer , thank you for your YouTube video. It triggered me to unclog it.
Been clogged for a few weeks.
I use a lighter and burn out the rests. then a thin wire.
Instead of physical force I always use the torch to clean my nozzles. As I heat them up first the remaining Filament burns away, then they glow red-orange and small specks of dirt glow yellow-white. I wait until these are completely burned away before cooling the nozzle.
Serveral people said it’s unwise to do because either I’ll get carbon deposits or the brass will melt. So far nothing bad happened after 9 month of use. Today I put them under the microscope to see for myself. Apart from strong surface oxidation they look good to me.
The first picture is a brand new nozzle at 100x magnification.
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The second picture is the torched nozzle. I tried to clean away the oxidation with 600 grain sandpaper but you can still see it in some places. Also 600 is way too rough.
(Photos taken with my smartphone through my Leitz microscope)
missing/deleted image from Google+