Scrape away as much snow from the rebar as you can with a shovel. If snow has been falling for several days, you may have to start by digging out the rebar. Ensure that you are properly dressed for the elements before beginning a long dig.
Sprinkle bagged salt over the rebar, to quickly melt any snow that may have found its way between the bars. Allow the snow to melt for 2 to 3 hours, reapplying salt at regular intervals if snow is continuously falling.
Pour several pitchers of warm water over the rebar, to melt any chunks of ice and wash away the salt granules from the metal.
Don a pair of thick gloves, and move the rebar to a new location. If possible, relocate your rebar to an interior location where snow cannot collect. If you can't place it indoors, cover the rebar with a large tarp and weight it down with cinderblocks or stumps.