How to Remove old ones: Remove the old ones from the Backguard by unscrewing from back part and and from eyelet in the bottom part. ( one can use screw driver OR a Coin ) How to Fix: First insert the lock part in the base of the Backguard just by pushing firmly and moving slightly either side. Fix back part using Brass Screws in appropriate holes as per individual height. ( as shown in the instruction leaflet provided ) Follow the instructions provided along with the hinges to avoid damage in future and have long life service.