You will using a hammer, by putting the metal sheet on top of a rounded piece of wood- though a vice will help! Alternatively and perhaps easier will be to put extra bolts in the pieces of metal. Once the piece is loosely in place, you tighten each bolt a little at a time and the metal patches will be pulled into place. If you are doing this make certain you have thick & wide washers to spread the load/ force, as the bolt heads won't be wide enough. Its straight forward and you won't have any problems so long as you have enough bolts/ nuts / washers, a drill & drill bit, socket set, hammer & centre punch and have ordered the metal pieces the right sizes to cover the holes. 1.5mm thickness steel is plenty 1mm is ideal imo. The bolts should be short. Washers nice and wide. PS. The ugly shitter from Argos is still available,