Motorola Atrix 2 comes with lock bootloader and due to that installing CWM recovery or TWRP recovery through regular process isn’t possible. That’s where BMM comes in. A custom recovery such as CWM recovery or TWRP recovery is required to flash custom ROMs. The latest BMM aka Boot Menu Manager comes with CWM recovery which let you flash various custom ROMs. We at True Android already covered few custom ROMs including 4.4.2 KitKat and 4.3.1 Jelly Bean. We all know official Motorola Atrix 2 for now can only be updated to ICS, hence custom ROMs are only option to try out latest Android OS.
So, BMM is a very important app to have on your Motorola Atrix 2. Just like SafeStrap app, you need little knowledge before you start using this tool to flash ROMs and other utility. XDA member arnab came forward and shared this fine video tutorial to help out all Motorola Atrix 2 users.
Download Boot Menu Manager from Play Store: https://play.google.com/store/apps/details?id=se.pajn.bms.manager
In the fist part you will learn how to upgrade your Motorola Atrix 2 to Android 4.0.4 ICS from Android 2.3 Gingerbread. And in second part, you will learn how to root Motorola Atrix 2 and install BMM as well as how to use BMM or Boot Menu Manager to flash custom ROMs. He also explained multiboot and shared many important tips that surely help you out while flashing.
I hope, this video tutorial give you a decent knowledge about BMM. So happy flashing! [source]