Turn off the Ryobi band saw and unplug it from the power outlet.
Unscrew the wing nut and bolt from the saw table, which are located on the side -- in line with the blade.
Open the cover by unlocking both of the latches (on the side).
Turn the lock knob, the outer knob on the side, towards you to unlock the blade holder (also called the blade guide assembly). Turn the blade guide knob until the blade holder is halfway from the saw table.
Turn the lock knob away from you to relock the blade holder.
Unscrew the two screws that are lined up above the blade, holding the blade in place. Use a Phillips screwdriver.
Remove the blade guard, which is located behind the two screws.
Ease the tension on the blade by pushing the blade tension lever--located on the upper right hand side of the band saw--to the front of the saw.
Take out the old blade and discard it.
Put on a pair of protective gloves to handle the new blade.
Open the new blade and wipe any oil from its surface, if it has been oiled. Although the Ryobi band saw originally comes with a ¼-inch blade, the BS903 saw will accommodate a blade width between 1/8 of an inch and 3/8 of an inch.
Put the new blade through the blade guides, with the teeth of the blade to face towards the back of the band saw.
Make sure the new blade is centered.
Renew the tension on the new blade by turning the blade tension knob on the top of the band-saw platform.
Replace the blade guard. Retighten the two screws that you previously loosened.
Retighten the wing nut and bolt on the saw table.
Close the cover on the front and reattach the closures.