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We started our installation by removing all of the header flange bolts, most can be accessed from the top of the engine.
Some of the bolts can only be reached at the bottom of the car.
Once you get the old manifold and cat out, it is pretty easy to see how the long tube header is going to make more power. The old manifold is very very unequal length and has odd T type junctures in the primary tubes.
We tried wiggling the header up there but there was no way it was even going to go without a lot of doing. We discovered what all the bolts in the box were for. You need to get rid of all the exhaust manifold studs and replace them with bolts to make for more wiggle room.
We then ended up removing the motor mounts, steering shaft, loosening the AC compressor and removing the starter. Then we had to lift the motor.
Here is a look at just how tight the fit was. If there were some instructions it would have eliminated a lot of trying things and failing. It took a whole day to put the headers in but now that we've done it once, we could probably do it again in 3-4 hours. Borla, you should include some simple instructions with these headers. 
