When switching to a new Subversion (SVN) location or migrating your project, use the command line:
svn --username [your username] switch --relocate [old location] [new location]
If you are using SVN externals and needs to update it:
1. Checkout project using:
svn --non-interactive --ignore-externals co [location of project]
2. Update the externals definition:
svn --non-interactive propset svn:externals "[directory that contain external] [external location]" [project name]
3. Commit changes
svn commit -m "updated svn externals for branch XXX-XX"
Hope this helps!