The guys method of using recovery to backup recovery will only work on Philz… Not twrp as it does not always backup stock recovery properly. The proper way to backup stock recovery is..
1. Root your phone, which can be done by towel root or by just booting a recovery like he said,
fastboot boot twrporwhatever.img, then flash supersu
2. Boot phone that has stock recovery
3. adb shell
4. su "watch your phone to grant root adb access if you haven't ever done it"
5. dd if=/dev/block/mmcblk0p43 of=/sdcard/recovery.img
6. This will put flashable recovery.img on your internal sd card. Copy this and save it for later
7. "fastboot flash recovery recovery.img" will get you back to stock recovery, "fastboot flash recovery twrporwhatever.img" to flash custom recovery.
where to boot it??
i have to boot my phone in bootloader or boot into system?
step 4. will i find adb shell when i boot into system? and what to do with it?
am a beginner i don't have much knowledge about this.