Emacs Dired rename many files

This can easily be done using dired:

1. Enter a dired view of your directory

2. Switch to writable dired mode (wdired-change-to-wdired-mode): C-xC-q

3. Edit the file names listing as if it were a normal buffer (for example using a keyboard macro or a rectangular selection or query-replace). Here is a regexp-based solution:

   C-M-%\(VAR.\)_\(..\)RET\2_\1RET

4. Finish editing (wdired-finish-edit): C-xC-s or C-cC-c

You’re done!