If you have updated past 3.55 and you are currently on 3.56 or 3.60 then you'll have to wait for a new method as nothing will work for you.
If not then you can install the original 3.55 firmware and install a custome firmware over that such as Waninkoko's PS3 Custom Firmware 3.55 or Wutangrza PS3 Custom Firmware 3.55.
For backup support you will need Multiman.
Please search for installation guide on the site, which will give you more detailed instructions.
Never Get in the way of progress!