Put 3.55 OFW on your usb stick. Make a folder on the USB stick called PS3 and within that a folder called UPDATE. Put the OFW 3.55 in there. Stick the usb stick into your ps3. When you go to update options select Update from memory device. Here's link
You must login or register to view this content.
Then once this is done and installed. Repeat the process with custom firmware KMEAW CFW
You must login or register to view this content.
Then once your running this you can install package files on ps3. Don't put the pkg file inside any folder on USB. Heres a link for the blackbox ftp server.
You must login or register to view this content.
Some pkg files are signed, and can't be installed depending on the CFW, shouldn't have any problems with KMEAW