Hi David,
SSID looks good and password easy enough. The SiB should see that SSID, no reason not to, just who knows, maybe some incompatibility between the AP and the SiB on that firmware.
In terms of instructions, I have attached an image for you to see instead as making a video will take too long and can't attach videos here either.
https://www.simp.net/support/20220822_124053.jpgThe image shows 2 arrows in blue, here are the 2 locking balls that hold the majority of force of the cover in place.
The circles show other locations of these same locking balls but they have far less of an effect on the holding of the cover down.
The way WE remove the cover is by putting the nails of the index finger and the one next to it between the plastic cover and the base which has the battery jammed in between these 2 bits of plastic and then with both thumbs pushing down on the button. This makes the main section of the SiB slide down as you remain holding onto the cover.
BUT, another way to do it, is to jam something thin in the same area where the blue arrows are (but not quite where the ball is) just anything in there to make the plastic separate. Here's another picture:
https://www.simp.net/support/20220822_140039_HDR.jpgYou just need anything that you can put in there to separate the plastic and for the ball to have some clearance from the channel.
Be careful, don't use anything sharp that would cut you!
When you re-assemble, keep in mind the cap has a specific way to be placed back and the cover too, has only one way to fit back in.
Best of luck, should be easy once you lift a little the plastic on those 2 sides.
Regards,
Mark