After removing the plywood deck, I found wood needing replaced. How do I go about ripping the stringers length wise as I only need to replace the top 3 inches of woodl I did drill all stringers at various depths to find dry or wet wood shavings. I only need to replace wood around the area holding the fuel tank. Yes I did remove the tank. Just trying to make a good cut to replace with a new wood plug. thanks to all.