Changing Info.plist values via terminal
You can use defaults or plutil command line tools.

For defaults it looks like this:

defaults write /absolute/path/to/Info.plist CFBundleExecutable -string &lt;Executable&gt;


For plutil:

plutil -insert CFBundleExecutable -string &lt;Executable&gt; Info.plist 


Value after -insert is a key path separated by .. For example 

plutil -insert CFBundleDocumentTypes.0.CFBundleTypeExtensions.1 -string "scss" /Applications/Safari.app/Contents/Info.plist


will insert "scss" string deep in the path. Numbers after . are for arrays (they are starting with 0).