E3 Flasher

Hi guys, so I want to jailbreak my 2/3 year old PS3 Slim. So I know that you need to downgrade your current software version (In my case 4.55) to 3.55 and then update to 4.55 again but then with a jailbroken version of 4.55 or something else. But I heard you need E3 Flasher to downgrade your...