This was taken from another site
Download Dream-Explorer from plugin feeds most images should have it in there feeds
This will allow you to browse to etc folder and as long as you have 2 file types passwd & passwd-
scroll down to passwd and Delete it
next Rename passwd- to passwd and save
Re start your box & you should be good to go as i have recovered many boxes with unknown root passwords with this procedure ( not my comments )
I cant test it for you as im copying some movies from the HDD on my box at the mo
But worth a try
No guarantees though
If you want to wait about an hour I can test it for you