First of all it cannot be done that way anyway, windows requires there to be at least one Admin account residing on windows as default.
You cannot demote an Admin account to a normal one if only one resides.
You have to create another Admin account to then demote the other Admin account to a Standard account. But in doing so you create a problem where UAC user account control will then be enabled to the account you changed to a standard account from an admin.
And it will be a nightmare as every time you click on a program if the permissions are not set right it causes all sorts of head ache trust me.
Most likely you will get bugged to death while trying to run a program you normal would of had access to as an admin. and trust me it will be a world of pain.
Its set in that order for a reason, security. Anyway that is the order you do it in but you have been warned.