cd %~dp0

set directory=[ディレクトリ]
for /f "delims=" %%I in ('dir /b /s %directory%') do call :sub "%%I"

:sub
set fname=%1
set fname=%fname:[消したい文字]=%

for /f "tokens=*" %%m in (%fname%) do set fname=%%~nxm
ren %1 %fname%

goto :EOF