I have been trying to figure this out for a long time. I have a pretty typical Mac OS provisioning script:

https://gist.github.com/ryanpcmcquen/b2e608311f286a4ab3e1

I would like to change the Mission control shortcuts to all be Ctrl+Alt+... instead of Ctrl+.... For example, the default is: Ctrl+Up to activate Mission Control. I would like to change this to Ctrl+Alt+Up, because the current shortcut conflicts with other programs I use.

Note that I am already aware of how to do this through System Preferences > Keyboard > Shortcuts, I am looking for a scriptable, command line solution.

EDIT: Thanks to @user3439894 I went through and made a script to change all the plist keys to what I want them to be. The only issue is, it does not work. :-(

Here is what I have so far:

#!/bin/bash
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 32 "{enabled = 1; value = { parameters = (65535, 126, 2883584); type = standard; }; }"
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 33 "{enabled = 1; value = { parameters = (65535, 125, 2883584); type = standard; }; }"
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 34 "{enabled = 1; value = { parameters = (65535, 126, 3014656); type = standard; }; }"
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 35 "{enabled = 1; value = { parameters = (65535, 125, 3014656); type = standard; }; }"
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 79 "{enabled = 1; value = { parameters = (65535, 123, 2883584); type = standard; }; }"
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 80 "{enabled = 1; value = { parameters = (65535, 123, 3014656); type = standard; }; }"
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 81 "{enabled = 1; value = { parameters = (65535, 124, 2883584); type = standard; }; }"
defaults write ~/Library/Preferences/com.apple.symbolichotkeys.plist AppleSymbolicHotKeys -dict-add 82 "{enabled = 1; value = { parameters = (65535, 124, 3014656); type = standard; }; }"
chown -Rf `whoami` ~/Library/Preferences/com.apple.symbolichotkeys.plist;
defaults read com.apple.symbolichotkeys