Disconnect the Ryobi miter saw from its electrical outlet.
Push down on the saw arm, pull out the arm locking pin located on the back of the saw and raise the saw into its upright position if it is not already in the upright position.
Loosen the Phillip's screw that holds the blade bolt cover into position on the left side of the saw. Rotate the bolt cover and blade guard upward to expose the blade bolt.
Press the spindle lock button located inside the handle, then rotate the blade by hand until the spindle lock engages the blade.
Turn the blade bolt clockwise with a wrench to loosen and remove it.
Slide the blade off the arbor and slide the new blade onto the arbor.
Tighten the blade bolt counterclockwise with the wrench.
Press the spindle lock button to release the lock.
Slide the blade bolt cover and the blade guard back down to its previous location and tighten the Phillip's screw.