A short update:

I tried to fix the problem with some wire but unfortunately I ran into a new problem: The extruder does not heat up anymore. I contacted the Solidoodle support in this matter but have to fix this issue first before I can solve the original problem.

Elias

before you take too much apart though.

you should see that there are four screws.
the top left screw and bottom left screw (are pretty obvious)
then you also want the screw that's right next to the black barrel thing (peek)
and the screw directly up from this, (not the highest screw in the assembly, but the one just below this.

these are the screws that attach the jig saw part (the plexiglass thing) to the stepper motor.

so just loosen these screws without fully removing them to start with and see if you can use tweezers to remove that jammed bit of plastic once the motor is loose and can wiggle a bit.

also, sounds like you have a clogged nozzle. (which was the original problem)
there are some good threads on this forum and the wiki on clearing clogs.
start by poking a thin wire into the nozzle from beneath, after that try removing the nozzle by holding the black barrel with some pliers and twisting the nozzle with a spanner, (it works better whilst the machine is hot and you;re not trying to crack apart an ABS rod of plastic inside the brass barrel.

please forgive, but i am a noobie. I managed to set up my Solidoodle after some hick ups but now i am in big trouble and need your advice.

All started with the extruder not working properly. The extruder stops spitting out the filament from time to time during printing. I cannot give an exact reason why, but normally reinserting the filament does the trick. But since yesterday the situation got worse and worse, after two or three layers the noddle gets jammed and stops inking out the filament... I tried to improve the situation by cleaning out the cog wheel which pushes the filament ahead with a little brush, as some debris was stuck between the gear. Unfortunately the problem reappeared after a few layers printing properly. But this time the filament was pushed out to the left side of the cog wheel instead of exiting the extruder through the noddle. It is completely jammed turning the cog wheel doesnt move it at all. I have taken a picture of this mess.

So there are two questions: How do i fix the current jam without destroying the extruder and what may be the main causes to look for jamming the noddle regularly?

To give you some background knowledge: I am noobie and therefore using the default 0.3 settings and printer worked for the last couple of days without any serious problems before the trouble started. I have not changed anything i am aware of causing any risk...

Thanks for your advice.

Elias