From the backend of your Joomla site (administration), access the J2XML Import Manager by going to Components -> J2XML.

Upload xml file

Drag and drop the xml file into the drag and drop area or click the or Browse for file button and select the xml file on your local machine.

The import process will run in background. Do not change page.

Options

Import

Fields
Import Custom fields
Images
Import Images

Users

Users
Import Users
Keep Ids
Keep the original user ids
Password
Import user password. Otherwise, a new password will be generated.
Super Users
Import users who belong to the Super users group.
User notes
Import user notes.

Notification Mail to User

If you do not want to send the notification to the user after importing an account, you must disable the option Notification Mail to User of the plugin "User - Joomla!"