Front brake is stuck

[therockbg]

Hello guys and girls. A few days ago i changed my front brake pads with new ones so i can go to inspection ... sadly they said i need to change the brake disk too.
But i have a problem with my pads - they are stuck for the disk itself - the cylinder on the caliper does not really go back and the brakes are overheating ofcourse and that is a problem.
Has anybody had similar problem and how am i supposed to fix it ...

I think it might be important to say that i made a complete brake fluid bleed from scratch - everything was empty and full with air so i had to bleed them ofcourse ... could i have done something wrong with the air-bleeding too?
I also noticed that it was extremely hard to get the cylinder back in the caliper even when i got the brake lines off .... could this sticking be a problem from the caliper itself? Is there any way to find the problem easy enough?
Thanks in advance from one of the few GZ250 riders in Denmark.