Hi, and welcome to the forum!
I'm not aware of any manuals the describe the process of removing the front clip and the firewall, the scope of that work is pretty much beyond the scope of typcial repair manuals. When I removed mine I primarily referenced the Assembly Instruction Manual. Although not specific to disassembly, it shows how all of the panels are attached an bonded together. Once you know this information you can then remove those points of connection/attachment to allow each component to be removed. Just take your time, study the car, and make sure you understand how everything is put together before getting started.
I've been working on my project for over 4 years now and have over 700 hours into the project so far (and an equal amount invested in researching and planning the work). It's been a slow process at times, and I work on it when I feel like it. I could push myself harder, but I don't want to turn my project into a "chore" or a "second job". When I first started life was a bit less hectic for me so I was able to put in a good 10-20 hours a week on weekends. Now I'm lucky to get 6-8 hours in a week.
Regardless, I continue to plug away and each week brings me one step closer.
Good luck with your project, and feel free to post as you move forward with your project!