How can I force bios downgrade at startup?

Recently i got a Dell M4500, but it came with locked bios.

I have researched a lot about it, but nothing seems to work to unlock it.

Even contacted Dell Support, and they have generated a not working password for me.

So i need a method to flash an other bios to change 1F5A tag, then i can unlock it easily.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2889612:0crwdne2889612:0 0
crwdns2934285:0crwdne2934285:0