OK, for starters, a Facebook page for an organization / business has to have at least one personal FB account attached to it as an Admin. That your wife (or whomever) is the Admin for her businesses FB page will be unknown to her followers, though, so there's no reason from a privacy perspective to remove her (other than the inherent reasons for not having a FB account to begin with).
In any case, your question is how to replace your wife as admin of her business page with the new account you've created.
Step 1 - Log-in to your wife's FB account.
Step 2 - In the upper right corner of the screen is a down arrow. Click it and choose "Use Facebook as [Wife's Business]"
Step 3 - Go to "Settings" (just below the down arrow)
Step 4 - Choose "Page Roles" from the menu on the left.
Step 5 - In the menu you now see, enter the email address associated with the NEW FB account you created.
Make sure you select "Admin" from the drop-down menu below the entry form where you enter said address - this is not the default setting ... Editor is the default setting, you need to change it. Then click "save."
Step 6 - Log-out
Step 7 - Log back into FB using your NEW FB account.
Step 8 - In the upper right corner of the screen is a down arrow. Click it and choose "Use Facebook as [Wife's Business]"
Step 9 - Go to "Settings" (just below the down arrow)
Step 10 - Choose "Page Roles" from the menu on the left.
Step 11 - You can now remove your wife's personal FB account. This will make your new FB account the sole admin in charge of/connected to her business page. The page itself won't change.
Can make all kinds of interesting things!
