1. Download the wanted firmware
2. Rename it from XXX.PUP to PS3UPDAT.PUP
3. Copy the file on any external device, such as an MS, on the ms0:/PS3/UPDATE folder
4. Run it under the PS3. Done.
2. Rename it from XXX.PUP to PS3UPDAT.PUP
3. Copy the file on any external device, such as an MS, on the ms0:/PS3/UPDATE folder
4. Run it under the PS3. Done.