If so, what do I then do with the tank?
Well, where do you live? And how much propane is left in it?
One option is to call around for propane companies and see who is willing to remove it.
Another option is to list it on Craigslist, "Free if you can move it."
A slightly more entertaining, if hazardous, option is to move it away from anything combustible, light a flare in front of it, step back to about 100 yards, and put a 50 caliber round through the end of the tank. And then hope you don't get a BLEVE. :D