[Stuck print head issue]

Hi,

 

I tried doing an overnight print and when I came back to check on the print nothing had printed and the plastic had fused to the print core. I am unable to remove the print cores from the extruder due to the plastic. I attempted to open the extruder to remove the print cores but it did not help. Is it possible to completely take apart the extruder to make it easier to remove the print core?

 

Has anyone experienced something similar to this?

Thanks