yea you need to find a welder.... from your pictures it looks like you would have to cut your downpipe a little and the best way to do it would be buy a flange to weld on the header going to down pipe so you can take it out easier in the future...re use the down pipe flange just drop it a coulple inches so headers will fit....or much easier would be to get it welded as one whole piece and like i said it will be more difficult to take out in future.