Well if you download a regular option file which would be PES2008_EDIT01, you just replace it with the file you have in you save file. If you haven't done any editing in PES2008 there shouldn't be a PES2008_EDIT01 file there so just put the PES2008_EDIT01 file that you dowloaded inside your save folder.
save folder is in C:\Documents and Settings\XXX\My Documents\KONAMI\Pro Evolution Soccer 2008\save