For stock ROM, you will need to press the power button once then the recovery mode will show up.But, it seems lollipop has a different method.
Booting into recovery mode on lollipop is of 2 methods.
Method1:This method works virtually for all android versions.
==>Download reboot recovery
==>Install and open then click reboot to recovery grant SuperSU permission and your phone should be in recovery mode
==>For android KitKat,jellybean,ginger bread e.t.c just press the power button once then recovery menu will shows up.
==>For lollipop, Hold down the power button then press the vol up once.
The major disadvantages of this method is that;
1. It will not work with a bricked device
2.It requires root premssion to force the phone to recovery mode.
Method2:This is the easiest just hold the power button +the vol up button
==>For android KitKat,jellybean,ginger bread e.t.c just press the power button once then recovery menu will shows up.
==>For lollipop, Hold down the power button then press the vol up once.
How To boot stubborn Phones to recovery
They are some exceptions where the phone will fail to boot to recovery mode and probably the phone is bricked.
==>Press the vol down+ the power button that will surely boot the phone to manufacturers mode(download mode)
==>Download android Flasher
==>plug on your USB chord then launch android flasher follow the screenshot above then you should be in recovery mode
