Guide: Switching from Bitcoin Core to Bitcoin Knots on StartOS v0.3.5.1

I’m trying to follow this guide, but there’s no “Reinstall” button for Knots. Am I doing something wrong? How can I make the switch?

I’m running StartOS version 0.3.5~1, which it says is the latest. I’ve tried System / Power / System Rebuild, and Restarting, but there’s still no Reinstall button (for any of the installed services - including Knots and Core).