Take your metal sign and punch 2 x tiny holes to the bottom of the sign using a metal cutter.
Funnel a 22 gauge wire through the hole.
Take your sign extender and add drops of rapper fuse glue to the back of it.
Take your sign extender and feed the wire through and place it to the back of the sign.
Use clippers to keep the sign and sign extender secure until the glue is dry.
Twist the wire to keep the sign extender attached.