I’ve added an uninstall command to for removing subprojects from being managed by externals.
ext uninstall some_project
To stop tracking some_project. This will not remove the files in some_project’s directory. If you want to do that, use the -f/–force_removal option:
ext uninstall -f some_project
This will remove all of the files and the some_project directory itself.
To switch a project to a new repository, you can do something like the following:
ext uninstall -f some_project ext install new/repository/url/some_project
This is the type of thing I added the feature for. I moved a couple plugins from subversion to git recently, and didn’t feel like manually changing the .externals and ignore features.