Need help flashing Echo Rom V8

I'm currently on another 5.1.1 Rom but a 5.0.2 base. So I should use odin and update that to the T-Mobile 7/1 (5.1.1 firmware. Then root and flash the Rom? Not sure if I need to update the bootloader and Twrp.

I use to be a flash whore but this process seems a little difficult. A step by step would be appreciated.

Thanks.

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