At sstep 4 which should i do?
If you can boot into your phone, do the following
Type in: adb
Type in: adb devices (This will give you a list of devices attached to your computer, so if your phone is correctly attached it should show up.)
Type in: adb reboot-bootloader
If you cannot boot your phone, do the following
Disconnect your phone from your pc
Power off your phone
Remove the battery
Insert the battery back in
Turn on your phone while holding BOTH the POWER ON and VOLUME DOWN button
Connect your phone to your pc again
only boot.img , boot_oncesc2 is for HTC one S