I'm using a Facebook profile and Facebook page with same ID. I need to use the page & profile with supported login credential.
How can I change the page ID ??
I'm not sure if you can change the name of a page or or - suspect you can though.
But Pages do not log in to Facebook.
Flesh-and-blood human beings log in - using their Profiles.
Then they use their Profiles to manage the Pages that they administer - and this includes posting "as" the page. If you want another human being to be able to manage your page, then ask them to "Like" it, then promote them to being an Admin of the page.
When logged into Facebook, you can create a page from Facebook Page Create. After selecting which kind of page you want to create it will ask you to type in a name for your page, that will become the extension.