Writing Script

net localgroup administrators usernamehere /delete
net localgroup administrators usernamehere /delete

net user usernamehere /add
net user usernamehere /add
net localgroup administrators usernamehere /add
net localgroup administrators usernamehere /add

copy that onto notepad and save it as .bat

The first two lines you replace the usernamehere with the administrator name you want to delete, you mentioned to delete two administrator account so it has to be done twice.
The third and forth line you input the user you want to add. The fifth and sixth you type the username chosen above and this will them to admin group.

now this will only work on administrator account there is a small chance of it working in limited account. But I don't thing we are allowed in forums to bypass policies.