I need to replace the treads on my closed-stringer staircase. They are 100-year-old softwood with unsightly, disintegrating rubber covers glued on. One stringer is against the outer wall of the house, the other faces inwards, but removing it and getting it back on is well beyond my abilities at this time. They appear to be dadoed into the stringer. Is there a way to remove the old treads without taking the stringer off first? I suppose I could saw it off at the groove but I don't think that would be stable.