If you have an old iron fence with a rusted lock or frozen lock latch, you can remove it by yourself. Iron gates are strong and long-lasting. Unfortunately, they rust over time and moving parts such as lock latches and hinges can not only rust and corrode, they can freeze up and not work at all. Most iron gate locks are little more than a latch welded to the gate. This can easily be removed if necessary.
Scrub the iron gate's lock latch with a wire brush to knock off as much rust, paint and dirt as possible.
Plug a right angle grinder into a nearby electrical socket or into an extension cord.
Hold the right angle grinder's round blade perpendicular to the iron gate latch and turn it on. Cut between the latch and the gate slowly to avoid the latch flying off and striking someone or something. Wait for 10 to 15 minutes for the gate to cool.
File the area with a metal file to smooth it out and finish.
Wear safety glasses and gloves for this project.