All finished, in all, I would call it pretty straight forward if you have the proper tools and equipment. I'll list the procedure now (A moderator may move this post to top and or sticky), but I caution, this is definitely NOT for the "I do my own oil changes" home mechanic. It can be done without a lift, but that will make things a lot more time consuming and less comfortable. I'm not going to post pictures or go too into depth, if you need pictures, you probably should sit this one out. It can be done by one person, but I'd suggest having a competent helper as it will literally cut the project time in half. Having done it, and spending a lot of time to find every way it's not done, if I had to do it again, I could probably get it done in about 6 hours using these instructions.
First things first, be ready to do an oil change and coolant change. Get the fluids and washers you'll need, as well as Maserati part
#109649 (Oil pipe gasket) and part # 154191 (Water intake cover gasket).
Starting under the hood, remove all engine covers, loosen both ignition junctions, coolant jug, and power steering reservoir. No need to completely remove, just create some flexibility. Remove the bolts holding the emissions pipe to both manifolds.
Now lift the car, remove both front wheels, and both wheel liners. You will see that you have access to some of the manifold nuts on both sides.
Drain the oil and coolant.
Remove all 4 O2 sensors, and make note from which side they came.
Remove the bolts holding the manifolds to the mid pipes.
Remove dust covers and bolts from the lower engine mounts on both sides.
Starting with the passenger side, remove the oil pipe from near the filter housing, and the other end at the bottom of the tank. It doesn't have to come all the way out.
Remove the lower rad hose, and the coolant junction on the side of the block.
Remove the heat shields.
You will now be able to access all of the manifold nuts, if you need additional clearance, lift the motor on that side alone.
Once all the nuts are off the manifold can be maneuvered little by little, while lifting and lowering the engine until it's out.
Driver's side is the same procedure, minus the oil and coolant lines.
Install the headers the same way they came off.
Soak all of the exhaust nuts in penetrating oil, this will save immeasurable time, pain, and frustration, as it will all but allow you to spin the exhaust nuts all the way to the flange by hand, instead of 1/8 of a turn at a time with a wrench.
The rest of the installation is the reverse of the removal...
One side note, I found that the exhaust shields no longer fit the new headers. I've found the ceramic coating to do a good job at keeping the heat contained, but I may wrap the oil pipe and ac compressor in fiber foil heat shielding eventually.
Ultimately, I feel it was worth every penny. The car and exhaust note is completely transformed especially at higher RPM (and I had catless exhaust manifolds to begin with). These used to go for over $5k, but FD has dropped the price to a more reasonable $2995, definitely check them out
4200 Larini Systems - Sport Exhaust Headers
Good luck, and feel free to PM me if you have questions.