My full question was:
================================
In settings, on the general tab, 5th item down, is the "Default text
style", with the directions
"(Use the 'Remove Formatting' button on the toolbar to reset the
default text style)"
But where is that toolbar with a button that says 'Remove Formatting'?
==================================
The button you refer to wouldn't change the default text style, but
just the text style of that one email.
However, you did cause me to notice the "T" icon on the toolbar that
was right in front of me in that 5th item down on the General tab of
Settings. So thanks!