RESTRUCTURE SVN REPOSITORY

Especially if you're using Subversion 1.4, see this answer for an alternative:

svn: replace trunk with branch.

Otherwise, move is the simplest way to achieve the restructuring. As @JoelFan said, move will work on directories, so you can perform this operation without a working copy:

svn mkdir --quiet --message "Restructuring" http://svnhost/svnrepos/trunk
svn mkdir --quiet --message "Restructuring" http://svnhost/svnrepos/tags
svn mkdir --quiet --message "Restructuring" http://svnhost/svnrepos/branches

then, appropriate move commands for your sources:

svn move --message "Restructuring" http://svnhost/svnrepos/dir01 http://svnhost/svnrepos/trunk/dir01

Note: If the existing repository has a structure like:

/repos
/projectA
/branches
/tags
/trunk
/projectB
/branches
/tags
/trunk

http://stackoverflow.com/questions/361801/how-to-change-structure-of-subversion-repository