Push on the latch on the battery pack and remove it from the Ryobi 18V One rotary saw.
Unscrew the blade screw from the saw. Remove the outer blade washer and the blade. Set the hardware in a safe place.
Brush off any sawdust from the blade and vacuum the inside of the saw to pull out any sawdust that may have gotten inside.
Pour 2 to 3 tbsp. of kerosene on a cloth and wipe the blade down with it to remove any pitch or wood gum from the blade.
Place oil on the blade where the inner washer rubs against it and place it back on the saw. Place oil on the side of the blade on which the outer washer rubs, and place the washer and screw back on the saw. Screw it in.