yep, its just really time consuming, and those heat shields are a b*tch to get out.
on the gts, you have to get the header out from the bottom.. you have to drop/unbolt the engine cradle and push it a bit foward to allow enough room for the stock header to come out so you can put the new header in.
i heard that for the gt models, you can take the valve cover off and you will have enough space to take the header out from the top. but thats just what i've heard/read.
good luck on the install.