OK, I used the Rockbox Installation/Removal Utility, and it appears to have worked. Except for one thing. During the process of removal/uninstallation, every time I was given an error message stating I needed to download the current Sansa firmware first. I tried that several times. This did not resolve the issue with Rockbox though. So now there is still a remnant of the Rockbox Bootloader on the device. The only way to bypass it is to hold down the Home button and Power button together whenever powering up the device. Otherwise, it boots up to some sort of dysfunctional Rockbox screen, which appears to serve no purpose. You cannot operate the device from that screen.
I just want the Sansa firmware on here. I don't want the Rockbox firmware on here anymore.