I actually tried to take the cowl off, but after removing the nuts from my wipers, the arms refused to budge, and I was worried I might end up having to replace the entire wiper assembly. I'm sure with some penetrating oil they would've come off but I decided to just suffer through.
I took a tiny flat head screwdriver and ran it under the coupler between the stock crossover and the TIP because the coupler was cooked on, then steadily pulled and twisted on the crossover until it gave. I was worried about cracking the TIP, but once the seal was broken, it came off really easily. I also loosened the coupler at the airbox to twist that pipe out of the way. Then took a little finagling to pull out the crossover, and it'll put a little pressure on the cowl, but not enough to risk breaking anything.
I'm kinda glad to not have had to remove the cowl, seems like an unnecessary step if the crossover is all you're doing.