Sorry to hear, as I wrote that workbook. That step 10 assumes that you have an Openplotter installation available, and it switches the TinyPilot to become a client of that Openplotter access point. I'll change the text to make that more clear.
I keep an HDMI display and a USB keyboard available for this kind of mishaps. With that, you can edit the file as hreuver mentioned. For similar problems on the pi-zero, I keep micro-hdmi and micro-usb extension bits.
WRT the UI language, I think that reflects your browser setting, so you'd need to change your browser preferred language to get this straight. To be sure, we'd have to wait for the east coast to wake up ;-)
I keep an HDMI display and a USB keyboard available for this kind of mishaps. With that, you can edit the file as hreuver mentioned. For similar problems on the pi-zero, I keep micro-hdmi and micro-usb extension bits.
WRT the UI language, I think that reflects your browser setting, so you'd need to change your browser preferred language to get this straight. To be sure, we'd have to wait for the east coast to wake up ;-)