[Verizon Galaxy S 5 Q&A, Help & Troubleshooting] israphial:
EDIT: I have successfully installed the Alliance ROM. Here's how i did it.

Prerequisites:

Your phone at at least 50% battery

A charge cable

MicroSD card that you can plug into your computer

Odin 3.09

SafeStrap, version 3.75 APK on your MicroSD card

Alliance ROM on your MicroSD card

NCG tar.md5 (the big file, not the kernel)

I started off on a rooted 5.0 VZW Galaxy S5. After some confusion, I downgraded to NCG (4.4.2) using Odin. After doing that, I went to Towelroot, got the APK, rooted, downloaded SuperSU from the play store (I had to sign into google at this point), installed it's binaries (NORMALLY! Don't choose the TWRP method), rebooted when it asked me to. From there, I installed BusyBox from the play store and installed it within the app. Then I installed Safestrap (version 3.75), which I had on my MicroSD card. I used the app My Files to navigate to my MicroSD and installed the APK. Then I installed it within the app, and when the "reboot to recovery" button worked, I rebooted into SafeStrap recovery mode. At this point, the Alliance ROM zip file should ALREADY BE ON YOUR MICROSD CARD, WHICH SHOULD BE IN YOUR PHONE. Now, you're going to press the INSTALL button to the top right in Safestrap recovery, and you're going to navigate to your MicroSD card. It might be already opened to that. Then you're gonna select the Alliance ROM and flash it. After it successfully flashes, reboot into download mode (if for some reason you aren't able to do it immediately, you get into download mode by holding volume down, home button, and power button at the same time). Now, using Odin, you're gonna flash the firmware that the instructions in the Alliance thread tells you to (here's the thread: http://xdaforums.com/verizon-galaxy-s5/development/rom-alliancerom-build-3-rom-control-t2818632). If everything works, it's gonna take a couple of minutes, optimize apps, and boot.

Huge thanks to Beans and his team for creating the Alliance mod, and huge thanks to Tulsadiver for helping me get through the process during my confusion.

Original thread below

Hi. I'll cut to the chase. I was an idiot and thought I could just flash the Alliance ROM from my SD card, but my phone is currently a factory restored 5.0. So, after unsuccessfully flashing Alliance ROM, I thought, well, I probably need to be on 4.4.2 to do this. So, what I'm wondering is, do I need to go back down to 4.4.2 to install Alliance ROM? And do I need Safestrap recovery to do it, or can I do it from stock recovery (home button+volUp+Power)? I did a lot of digging in the Alliance ROM post and there were no posts regarding my problem/question, probably because they're all experienced and I'm not (this is my first time trying to flash a custom ROM).

It SOUNDS like I need to flash a full stock tar using Odin, is that correct? Once I do that, I would be on stock wiped 4.4.2, I assume. From there, could I flash the Alliance ROM and continue with the instructions? Or do I need to root first and get safestrap and all that crap? I feel like Beans was really vague with his instructions on installing ROMs, but whatever. Please help though, I'm kind of stuck in the middle of this with a softbricked phone.

Thank you so much in advance, I appreciate it.

~isra

EDIT: Also, I was on ROOTED 5.0 Lollipop just before this. I just got so sick of lollipop, I was ready for something different. So here we are. To confirm, my phone is the standard retail SM-G900VZW model.

EDIT2: Apparently App Ops and SuperSU survived the wipe and, after downloading Root Checker, I can confirm that I'm still rooted... Huh.