It doesnt look to me that the shelf is attached to the wall but then you could just pull it out of the closet so im going to hope your not that stupid and for some reason you cant just pull it out. Those shelves even look like they come apart but anyway yeah a torch is one way to cut it in half but yeah not the best thing to do indoors if you have a circular saw that will work you can buy blades made for cutting metal but those bars look thin enough in the middle to cut with out fucking up a regualr blade. When you cut it stand to the side of the blade not directly behind it. It should be pretty simple but if some one put it in there, there should be an easier way to get it out so im doubting your intelligence at the moment. Whatever works.