At some time in the past, the interior stairs of the home I recently purchased had carpet pieces glued to them. Most of the carpet pieces are long gone but the adhesive remains. I would like to re-finish the treads but am unsure how to remove the adhesive without damaging the wood. Should I apply some product to soften the dried adhesive first or should I just sand them as is? I am a neophyte with respect to home improvement but someone told me to use an edge sander for the treads. Is this right?
Also, one of the treads has a horizontal crack through the middle. Can this be repaired or must it be replaced?