Change Dell Latitude 5400 Service Tag in BIOS

I'm swapping motherboards on a Dell Latitude 5400 laptop in order to gain Thunderbolt 3 port instead of DisplayPort. I want to change the service tag reflected in BIOS so that it matches the motherboard I'm replacing. In the past I've accomplished this with a Dell Utility (Dell Bios Reset or DSTCD) via bootable ISO, but those methods aren't working now. If anyone has an updated utility or another method for accomplishing this, that's what I'm looking for. Providing an iso file and a brief instruction would be perfect. Thanks!