The other end of the spindle and opposite knob is threaded so that this knob can screw on to the spindle and subsequently adjust for door thickness.
Thru spindle too short on door handle.
Push on the handle until it fits against the corresponding trim plate at that side of.
I do this most days easiest way to do it is to insert follower bar thats the technical term for the spindle into the door handle and through the latch in the door ensure door handle is.
The one that screws into the larger flat.
If that does not work try and use a thin scraper or similar to disengage the latch from the gap between door and frame.
It seems the original had broken so it actually was too short to fit where it belonged.
One knob is fixed permanently to the spindle by means of a grub screw through the neck of the knob.
It s nice being able to get through your door without too much trouble.
Remove the rosette off of the spindle.
Once door is open remove old latch and replace.
Take old latch with you as there are numerous different sizes.
Try and use a big flat screw driver to open the door where the spindle use to go.
Unscrew one handle and remove the spindle.
Remove the set screw securing the doorknob to the spindle then unscrew the door knob off of the spindle.