Is it jammed, because the motor worked, or is it just jammed in the bottom rails? In the first case it's difficult: you have to open the device and connect the drive to a voltage source of about 12 V DC. Another possibility: the side plate of the brewing unit can be unscrewed, but this is really ugly. Follow [guide|123977|this guide]
In the second case the brewing unit maybe removed by pulling firmly in the top left part of the brewing unit. Good luck!