iBooty v230 how to use to reboot

when preparation wording appears, press both home and power first 5 sec, within this 5 sec swich off the phone and just continue the press and power bottons keep in black screen, then relase power botton, but if have apple logo or itune logo appears, need still press the home and power botton until it return to black screen, then ibooty will install jailbreak booting command.