Unscrew one handle and remove the spindle.
Thru spindle too short on door handle.
If that does not work try and use a thin scraper or similar to disengage the latch from the gap between door and frame.
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.
Remove the set screw securing the doorknob to the spindle then unscrew the door knob off of the spindle.
Remove the knob and rosette from the other side of.
Mount the handle near the end of the the spindle on the spindle opposite the one that contains the larger flat ie.
Take old latch with you as there are numerous different sizes.
It seems the original had broken so it actually was too short to fit where it belonged.
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.
One knob is fixed permanently to the spindle by means of a grub screw through the neck of the knob.
Push on the handle until it fits against the corresponding trim plate at that side of.
Once door is open remove old latch and replace.
The one that screws into the larger flat.
Remove the rosette off of the spindle.