Z50-70 Bios update from 9BCN26WW(whitelist removed) to 9BCN91WW

Hi,
I requested and installed some month ago the whitelist removal from this site. Now I'd like, if possible, to upgrade to 91 from 26, because some problem of 26 with ssd and other...
Is it possible to mod 91? If yes, I'd like only the whitelist removal, Should I upgrade to 91, backup and install the eventual mod?
Thanks