Accedently Replace / Remove Directory From SVN

Problem

I have replace a directory from 'trunk' at revision 977 & now i want to rollback to revision 974 .....!

Solution
Simply follow these steps mentioned below:
1- $ svn merge -r 977:974 https://som_one.com/repos/home/trunk
2- $ svn commit -m "Recover Lost Directory"
3- $ svn update