According to SFGate, refinishing an iron bed generally involves removing the paint and sealing the iron with beeswax. Broken parts require professional services. Seal the parts in large black plastic bags and use washing soda to remove the paint.
Create the bags
Use 4-milliliter black plastic sheeting and duct tape to create bags to encase the bed parts. The bags should be a few inches larger than the parts they enclose. Seal the bags to reduce evaporation.
Use the sun
Place the bags in the area that receives the most sun. Place the metal bed parts inside. Add ½ cup of washing soda and 2 gallons of water. Fold over the end of the bag and seal it with more tape.
Remove the paint
At the end of the day, put on rubber gloves. Open the bags and remove the metal parts. Peel the paint off with a rag. If it is still stuck, place the bed parts back into bag, seal the bag and leave it overnight. Use wooden or plastic scrapers to help remove the paint. Dry all of the parts thoroughly to stop rust. Sand any remaining paint away to reveal bare metal.
Melt the beeswax in a microwave on low and apply to all of the bed's parts to prevent rust and give the metal a sheen. Polish it using a dry cotton rag.