Step 1. Download your option file.
Step 2. Once downloaded, extract the file using WinZip or WinRar depending on the format of the download, making sure that the first folder is called PS3 and then the next being SAVEDATA (these folders should already be created when downloading the option file)
So on your desktop once downloaded it should show, PS3 -> SAVEDATA -> (all files should be here)
Step 3. Copy everything on a USB and plug it in the PS3.
Step 5. Now you have to do the long process of copying all the files. MAKE SURE YOU BACK UP YOUR CURRENT EDIT DATA JUST IN CASE THIS DOESN'T WORK. The Edit Data from your downloaded option file is key and must be copied. It'll ask you to overwrite and will also give you a warning that you cannot earn any more trophies.
AN OPTIONAL METHOD -
To avoid the trophy message you can upload the OF to a secondary account - the message will pop up. Then go back to your main account and then just copy the data (Both edit and kits onto your main account).
The only problem with this method is, you have to copy everything twice. (Once to your second account, and then again (using PS3) to copy it over to the other account)
Minor files like Master League and Become a Legend files do not need to be copied as they have no effect.
Step 6. Once everything is copied, this should be all you need to do. Go into PES and the edit mode should be updated. (also, one thing to note is that if you used an option file that used player faces updates, some may not work and the player will be left with 'No Data' on the face. If this happens, just change the player from a 'Scan' face back to 'Default.'
These are images showing you what should be on your computer at Step 2! Note, this is just an example Option File and may not have the same files at the second stage.
This is the first stage, the starting folder is PS3 and then inside will be the SAVEDATA folder.
This stage shows all the folders that you have downloaded. Inside those folders will then be the images and files.
Also, if you're looking for an option file, I would suggest looking here. There are plenty of files which suit all different needs and wants.
 PES 2011
WENB have released 2 good option files:
There's also an option file which I highly recommend here.
I hope this helps you.
1. Can you have more than one OF in your game?
Nope because remember you're deleting and overwriting the edit data, which is the main thing for the Option file, so you can only ever have one, otherwise you'd just be overwriting your option files which would replace the old data. If you want another OF you can create another PSN account or something.
2. Will downloading an OF corrupt my Master League/Become A Legend?
No, because you've saved those ML's and BAL, therefore the game saves all the players in there etc.
3. What is the BLES code?
Wherever you bought PES from, that region will have a specific BLES code, UK is 01020 and therefore Option Files you download have to be specific to that BLES code otherwise it won't work. Your BLES code can be found on the spine of your game box.