Interior laundry room door leading into garage. Keyed door lock will NOT retract no matter what I do. Can't take door off hinges b/c middle hinge is one of those spring loaded kind that doesn't have a pin. Stopped by a locksmith this morning who said for $125 he would come out and take a Dremel to cut the back side off the cylinder that holds the latch bolt. this would allow him to retract the latch bolt, open the door, then solve the problem that he thinks has something to do with the strike plate. I didn't follow his explanation totally as he spoke fast and didn't want me to just do it myself. But that is what I want to do and save $125. Or bust the lock (without messing up the door) and just install a new lock for $50 or so. Can anyone suggest how I do either? Note: however if I have him out he could fix a problem with another lock I have. :)
I also can't figure out why I can't pull off the other side of the door knob. Anyone tell me what is holding it on?
Pic below.