Re-map keys on keyboard
Solution 1:
BetterTouchTool ( http://blog.boastr.net ) can re-map arbitrary keys. Under preferences, select the "keyboard" tab, then "+add New Shortcut", click in the "Keyboard Shortcut" then type the key you want to change. Then select "Trigger Other Keyboard Shortcut" and type in shift-opt-dash.
There might be simpler ways just for keyboard remapping, but BTT can do lots of other things too.
Hope this helps,
Karl
Solution 2:
Install and launch Karabiner. In the menubar open the menulet Karabiner -> Preferences. Then hit the tab "Misc & Uninstall" and "Open private.xml"
Paste the following lines into the opened xml file:
<?xml version="1.0"?>
<root>
<item>
<name>Swap Minus and Alt+Shift+Minus</name>
<identifier>remap.minus_and_optionlshiftlminus</identifier>
<autogen>
__KeyToKey__
KeyCode::MINUS, ModifierFlag::NONE,
KeyCode::MINUS, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L
</autogen>
<autogen>
__KeyToKey__
KeyCode::MINUS, ModifierFlag::SHIFT_L | ModifierFlag::OPTION_L,
KeyCode::MINUS,
</autogen>
</item>
</root>
and save the file.
Return to the tab "Change Key", hit "ReloadXML" and enable "Swap Minus and Alt+Shift+Minus". It should be the first entry listed.
If you are left-handed you may replace _L by _R in the xml file.