Jo.
Well-known member
There is an add-on for this - we have it installed and it works brilliantly.
http://xenforo.com/community/threads/xfb5-xfr-merge-double-user-post-v-1-2-0-en_ru.6264/#post-131752
http://xenforo.com/community/threads/xfb5-xfr-merge-double-user-post-v-1-2-0-en_ru.6264/#post-131752