2001 neon obx header HELP!!!

my cousin got a obx stainless 2 peice header for his 2001 2.0 sohc neon we got it yesterday but ok the down pipe peice at the end of it where it should connect to the exhuast underniethe the car it has no flange do you have to take it to be welded or is the stock exhuast this way too i havent looked under it yet i thought i would ask in here maybe someone with same car has put this header on it... any advise would help thanks