You won't be able to rename subdirectories on Microsoft Windows using Perl, at least not easily, portably, correctly and without a lot of arcane folderol using Win32 modules. Perl can't handle folder and file names with any characters in them outside the Basic Latin and Latin 1 Supplement blocks of Unicode.

See Is File::Find Unicode-(Conformant|Compliant|Enabled|Capable)? and dos path accents.