I need to Delete an Apple ID

See Legal - iCloud - Apple (US) which states:

A. Voluntary Termination by You

You may delete your Apple ID and/or stop using the Service at any time. If you wish to stop using iCloud on your device, you may disable iCloud from a device by opening Settings on your device, tapping iCloud, and tapping ”Sign Out”. To terminate your Account and delete your Apple ID, contact Apple Support at https://support.apple.com/contact. If you terminate your Account and delete your Apple ID, you will not have access to other Apple products and services with that Apple ID. This action may be non-reversible. Any fees paid by you prior to your termination are nonrefundable (except as expressly permitted otherwise by this Agreement), including any fees paid in advance for the billing year during which you terminate. Termination of your Account shall not relieve you of any obligation to pay any accrued fees or charges.