Residential & Commercial Security - Locks, Keys & Dead Bolts - Schlage F51 inside knob removal

Hello,
We have several Schlage F51 locks that have been in use for awhile and have been pleased with them, so when replacing locks at another location we decided to go with the F51 as well.

With the ones we have in place, there is a "catch" on the neck of the inside knob which can be depressed with a screwdriver allowing the knob to slide off so that the screws can be installed. On the ones we just received, the inside knob doesn't have anything like that, and I can't figure out how to remove it. Unless it comes off, it is impossible to install screws without using a small right angle screwdriver. On the neck of the inside knob there are two dimples on one side and a little slot on the other. (But no "catch".)

Is there a way to remove the knob with these, and why would they be different from the other F51 locks that we have installed? Thanks for your help!

There are several brands of residential knob locks that don't use a "catch", rather, the two phillips screws are accessed with a #2 phillips screwdriver with a sufficiently long shank so as to place the handle beyond the knob. While the angle of the screwdriver is not ideal, the 25 degrees or so off-center is managable if you push pretty hard on the screwdriver to get it started. If you do have an offset screwdriver, you can use it to get them started, as well. Pull out on the knob gently as you unscrew them in stages, so that the screw heads stay close to the rose, so you can maintain a minimal angle.

Installation is reverse, start screws with fingers, pull out on knob so that screw heads are close to rose, tighten in stages.