Yes you can of course.
Just click here:
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After you have downloaded the file, make a folder on your USB Flash Drive called PS3 than make a new folder Update and than drag the file into that you have just downloaded into the folder.
Now go to your PS3, go to Update System, and click to update with a Store Device, simply just follow the instructions and you are done.
btw, you can even get onto FTP Server ect. if you are using the old Firmware :O
It's the same way as the CFW, just with a different file :p