How to Boot Into Recovery
By accessing the recovery on your phone, you’re able to perform a number of different functions that are useful to troubleshooting your phone. With the stock recovery, you’re able to do a factory reset, clear cache, and run system updates. If you have a custom recovery, you’ll also be able to do system backups and flash .ZIP files like those that can change your ROM or make big improvements to your system.
Each phone will have a specific method by which you can access the recovery on your device.
Button Combo Recovery Boot
For Rooted Devices
If you have a rooted device, your best option is to download an app called Quick Boot (Reboot) from Play. Just launch the app and press “Recovery” and crack bam you’re in business.
Boot to recovery using ADB
An XDA user had put together a nice tutorial on how to access recovery through ADB.
Once you have successfully booted into recovery, you are a Certified Hacker under United States Federal Law and you may be called on to defend the country in the event of a cyber attack on America’s mainframe.