How can I link my iCloud to my new Apple ID to upgrade my plan?

Paulpunzalan922 wrote:

I already creat[ed] a new Apple ID [becouse] because I forgot my password of my old Apple ID..

This was a huge mistake. Each Apple ID is treated as a different person. There is no way to transfer anything from your old Apple ID to your new one.

So at this point, you basically have two choices how to proceed:

1. Continue using your old Apple ID and forget about the new one. Retrieve the old Apple ID password as follows: If you forgot your Apple ID password - Apple Support
2. Use the new Apple ID and forget about the old one. Thoroughly cleanse your Apple device(s) as follows, then “move in” using the new ID. What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support or What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

How do I 'cleanse' my devices in order to insert my new Apple ID? I cannot seem to remove the old Apple ID which was hacked and I no longer have the password to unlock it.