There are several ways to set the glyph name.
Glyph names are automatically converted to a ‘nice name’ (e.g. if you input "afii10017", it will be converted to "Acyrillic").
If you don’t know the exact glyph name but the unicode value, you can use "uni"+unicode hex value. (e.g. uni0410 for the cyrillic uppercase "A").
Select the glyph in Font view
Press ⏎ or click on the glyph name.
While typing, a popup will suggest a valid name.
Select the glyph
Remove any selection if you are in selection mode
In the inspector pane, click on the glyph name.
While typing, a popup will suggest a valid name.
Select one or more glyphs in Font view
From the menu choose Edit > Find > Search And Replace ⌘⇧F.
In the dialog, put in the search string and replace string, then click
.