Avatars Redirection Issue

Hi everyone,

We had follow this tutorial :
http://codex.buddypress.org/getting-started/install-buddypress-on-a-secondary-blog/
to moove buddypress on our blog number 7.

All succeed except the step 3 : Keep your old BuddyPress user / group avatars.
We added the two lines on bp-custom
define( 'BP_AVATAR_UPLOAD_PATH', 'www/mgtv2/htdocs/prod/wp-content/blogs.dir/1/files' );
define( 'BP_AVATAR_URL', 'http://www.ma-grande-taille.com/wp-content/uploads/avatars' );
but nothing happened.

Somebody can help us ?

Sincerely Regards,
Fashion Fox