You are in control.
A 529 plan requires three entities: an owner, a beneficiary (usually a potential student), and a successor or death beneficiary. Social Security numbers and physical addresses of the Owner and Beneficiary will be required to make an account which should be easy on the state 529 plan website. A few states require no minimum deposit to keep the account open.
The account owner retains complete control of the account funds until death. He or She may pull the funds out or close the account at any time (taxes or penalties on earnings only could apply). An account owner may grant a financial advisor or firm limited power of attorney authority to obtain information about the account and to perform tasks on the owner’s behalf.
A major benefit of the 529 account is the ability to change any of these entities (owner, beneficiary, or successor) at a given time without fee or penalty! An owner can change the death beneficiary. He or She can transfer funds between related beneficiary accounts at any time. The owner (maybe a grandparent) who no longer wishes to contribute or manage an account may transfer their ownership to a relative or even the beneficiary themselves, provided the beneficiary is over age 18.
No statement or example on this site should be considered a specific recommendation for your personal situation. Investing and tax strategies each carry significant risks. Examples herein may not apply to your situation. Please consult your estate attorney, tax advisor, or financial advisor for personal advice.