Flashing is easy
After you root and install custom recovery, all you have to do is download the ROM and transfer it to your SD card
Enter recovery, wipe dalvik cache, cache and data, find the ROM ZIP file, and flash!
The only way to soft brick your phone is to flash the LTE version of the rom or to flash rom without wiping cache and data
I personally do a full wipe (dalvik, data, system, internal storage , cache)