Aagh help door knobs!!

[CollectingCoins]

I want to replace the door knob on an internal door. I cannot get the original one off. Cannot see any other screws to remove. Tried pulling/jiggling etc!! Any ideas? Photos attached

Don't you need to undo that sort of allen bolt thing in the side of the shaft?

Or if all else fails, you can always try hacksawing through it. It'll be hard work but sometimes needs must.

Need an Allen key for the middle section

Hacksaw it will be if all else fails!! I’ve bought the new door knobs and I will use them come hell or high water!! Thanks all will go rooting for my supply of Allen keys!!