The following are prerequisites for this to work:
- Rooted Verizon Samsung Galaxy S5 (SM-G900V) with unlocked bootloader.
- TWRP custom recovery installed.
- 7-Zip installed on your PC.
- SuperSU downloaded to the top level directory of a USB flash drive.
- A USB OTG cable.
- Download full stock firmware.
- From the above archive, extract system.img.ext4, boot.img, modem.bin, NON-HLOS.bin, into a new folder on your PC.
- Open 7-Zip.
- Navigate to the folder containing the files from Step 2.
- Select all files from Step 2.
- Click Add.
- In the Add to Archive window that pops up, enter a filename and desired path.
- Click the Archive Format dropdown.
- Click tar.
- Click OK to make the files into a .tar archive
- Flash the .tar archive from Step 4 in Odin using the AP slot as described here.
- Boot into the ROM and set it up as you would a new phone, including updating all the apps on it.
- Boot into TWRP.
- Connect the USB flash drive containing SuperSU to the S5 using the USB OTG cable.
- In TWRP, tap Install.
- Tap Select Storage.
- Tap USB Storage.
- Select the SuperSU .zip file.
- Swipe to flash SuperSU.
And that’s it. This will give you a fully stock, rooted Lollipop ROM you can boot right into.
If you run custom ROMs, the stock ROM is pretty useful to keep handy as some troubleshooting methods (especially advanced ones involving the baseband) work on it only. As such, it’s a pretty good idea to back it up so you can restore it as needed. Instructions found in Phase 9 here.