However there are comments in the SVN code that imply changing the protocol is not going to work, even with the switch command. So the only safe way, AFAIK, to change protocol is to delete the local copy and then grab a new copy using the svn: protocol.
Does SVNKit support `svn relocate`?
Code:
svn info | grep -P '^URL:' | perl -pe 's/^.*?https/svn/' | xargs svn relocate