after a quick search, I found.
http://www.brothersoft.com/games/tools_and_editors/directx_9.0_uninstaller_51965.html
Seems to be free and its rated rather highly, after uninstalling, you could use the directx installer from oldversion.com as i posted above.
If this program doesn’t work.
you could try
http://www.majorgeeks.com/download4347.html
It says 12.95 shareware… so it may be free for a one time use… I really don’t know… its also rated rather highly.
And I am claiming no responsibility for any programs listed above, Since I do not have much experience rolling back directx or installing an older version… It has always just worked for me…