How do I view a page with a different character encoding in Firefox?

I'm looking at a web page and the characters are all ASCII gibberish. I have reason to believe the web page is in Shift-JIS character encoding. So, I want to view the page in that encoding.

I'm using Firefox 29, and after much searching, both in the interface and online, I can't see how one can select to view a page in a particular character encoding. It used to just be in the View menu. Now... where is it?

1. If you press F10 or Alt, you get the old menu bar temporarily back

   

2. Under View » Character Encoding you see "Japanese (Shift_JIS)"

   

In Firefox 93+ one could fix the wrong page encoding by clicking to View >> Repair Text Encoding from the Menu (F10). Obviously, in the recent versions of FF, Mozilla (Text Encoding no longer available in the Firefox menu panel) has decided to remove the old way of changing the page encoding.