A script that will change name of local admin from "1" to "something" for all the computers on the network

thanks oBdA.
is this going to apply to all the computers in the network?
Do the computers have to be restarted to make the change?

To which machines it applies is only depending on where you link the GPO with the "rename administrator" policy.
For starters, you can just link it to an OU with just a few test machines in it. Once you've made sure it's working as it should, apply it to the other OUs where the machines are  for which you want to have the administrator renamed.
The machines don't have to be restarted, but it might take up to 90 minutes to apply the setting by themselves (unless you run a "gpupdate /target:computer" on them).

thanks again
how about change the password as well?

thanks, I will try them

Thanks oBdA
it worked! Great solution!