I am a newby with this technology. I have 50 Dell 755's at BIOS A03 & what to upgrade them all to A13 simutaneously.
Is it possible to use Any of the AMT tools for this purpose? If so, how should I go about it?
It all depends. Are you talking about currently provisioned machines. Do you have a way to distribute software a la Altiris, SMS/SCCM? From the SCCM standpoint, you can create a collection, enable Wake On LAN in your advertisement and as long as the machines are provisioned, the SCCM server will leverage vPro to power on the machines and run the program to upgrade the BIOS.
You can use O755-A13 -nopause to force the reboot if you are pushing it off hours and set that the program forces the reboot. You can then create an inventory collection that will query the BIOS level and tell you if they were successful or not.