There are some articles on the internet about this. Basically: one side would be fried, the atmosphere would be superheated, and you would have nasty smog all over earth afterwards, making sure that seeds wouldn't grow because Earth would be pretty dark. Oh, and the ozone layer would be stripped off, so the bottom of the ocean might be survivable but apart from that you'd want to be underground during daylight.
In 2008 there was a GRB that occurred about 7.5 billion lightyears away - it was visible with the naked eye, and was aimed straight at Earth. Just imagine what something at 75000000 million lightyears would do - let alone at 7500, about where WR104 is.