One approach--Go into Tools | Customize Menus. Click on Commands, then
All Commands, then tab to the Command List. Type t o o quickly to jump
you to the Tools section of the alphabetical commands list and find
ToolsCustomizeRemoveMenuShortcut. Drag it to the Work menu and drop it
there.
Now, you've got the remove command always at hand and can forget all
about the keyboard shortcut, which sometimes is interfered with by an
Apple Zoom command, and sometimes doesn't work for other reasons, all of
which you probably will have forgotten by the time you need it again,
forcing you to re-investigate why it doesn't work in six months.
But I'm sure someone else will also post the standard interference
fixes, which I don't remember at present. One of them has to do with
whether you are using the hyphen or the minus key on the number pad, and
another has to do with whether System Preferences | Universal Access has
Zoom turned on, in which case the system hijacks cmd-opt-minus.