In general, you have to go to the Users menu, find the users you want to remove and move these users to the trash.
On PS5
Here’re the steps to remove accounts from the latest Sony PlayStation console. The first step is to close any game or app you’re playing or using. Ensure you’re not running any game or app before completing the following steps. Let’s continue: These are all of the steps you need. You can add back the accounts with the “+Add account” button, so the damage is not permanent. After you delete the account, you can keep playing as usual. Regardless, you should check you’re using your account like so: This method allows you to delete family members as well. On PS4, you need to delete these accounts with other steps.
On PS4
Like on the PS5, the first step is closing any game or app you’re using: Let’s continue by closing the accounts: Lastly, you should ensure you’re using your account after you delete the others: