Insert steel bracket into plastic bracket. To install with inside sliding door? Close movable door. Locate rotating bracket on door jamb with release lever up. Drill 1/8" holes for the two domed head screws. Extend bar with locking saddle to edge of sliding door. Use lever to locate and drill 1/8" holes for the remaining screws. To install with outside sliding door? Close movable door. Locate rotating bracket on nonmovable door with release lever up. Drill 1/8" holes for the two domed head screws. Extend bar with locking saddle to side of sliding door frame. Use lever to locate and drill 1/8" holes for the remaining screws. Care must be taken that locking saddle is positioned at least 2" above the sliding door handle. Storage: to store: Release and allow smaller bar to telescope into larger bar. Raise up flush against door jamb. To operate: Close door and extend sliding portion of bar unit end drops into locking saddle.