Yes you should always install the same version number OFW before installing CFW especially if you are changing to a different CFW.
---------- Post added at 03:23 PM ---------- Previous post was at 03:22 PM ----------
Originally posted by nextgenafter
I just got a ps3 fat that is on 3.15
are these the right steps to jailbreak it to 3.55
1. upload 3.55 ofw into the ps3
2. upload kmeaw cfw after?
or are there any other things I must do between that before I properly jailbreak it?
BTW, yes that is all that you need to do.....there is no other steps. But you will most likely be better off by installing the Kmeaw CFW through the recovery menu.