It can be modified, this is what i had to get done, the pipe can just be shortened, but the hole has to be enlarged to suit the larger exhaust housing outlet on the turbo, and a splitter welded in to separate the wastgate gasses.
It was basically a big hassle for me, had to take the pipe to get modified, took a couple of days, cost $150, and was far from a straight swap over, which installing a highflow normally is.