How can I map a Service's Keyboard Shortcut on the Command Line?
The service shortcuts are stored in pbs.plist and can be modified like this:

/usr/libexec/PlistBuddy -c 'Delete NSServicesStatus:"(null) - \
  servicename - runWorkflowAsService"' ~/Library/Preferences/pbs.plist 2&gt;/dev/null
defaults write pbs NSServicesStatus -dict-add '"(null) - \
  servicename - runWorkflowAsService"' \
  '{key_equivalent = "^~@1";}'


Source: https://apple.stackexchange.com/users/3936/

^ = control, ~ = alt, @ = command; replace servicename with the name of the service