Handles removing on UPVC Windows

Hi. Have 5 double glazed windows (UPVC) which have no keys. I have decided to change the handles. When I have done this before I unscrew the two screws holding the handle to the frame and then the handle just pulls out with the spindle. With these however they seem to be held tight. When I pull on them all that moves is the frame slightly away from the glass so don't want to brake anything buy forcing too much. Is there anything that might be holding them in place or do I really need to pull extra extra hard? Any help would be appreciated.
Thanks