dotCMS Users can be deleted, only if they are replaced in the system by another valid User.
If you do not wish to delete/replace the User, you can deactivate the User instead, which merely disables the User's backend login and prevents them from connecting to the system from the front-end or back-end.
To delete/replace a dotCMS User, first go to the System→Users tab, and then click on the name of the User, and then on User Details. Beneath the User's information and password, click the Delete button.
After clicking on Delete, you will be asked to choose a replacement User in the system. This newly selected user will replace the deleted user on all objects that were previously created/edited by the previous User.
Upon choosing a replacement User, and clicking Delete, you will be prompted to confirm the delete, and then the old User will be deleted and replaced by the newly selected User. Upon confirmation of the User deletion, you will be notified that the User delete process has started.
The deletion/replacement of the User can be tracked by clicking on the notifications icon in dotCMS header bar, next to your Username. The notifications panel logs each replacement on each object until the user is finally deleted.