You can change the WordPress user roles by following the given steps:

Step 1: Open phpMyAdmin on cPanel.

Step 2: Open the wp_usermeta or xxx_usermeta table in the database as highlighted. (wp_ is just prefix, your table prefix may be different)

Step 3: In wp_usermeta table, you can find wp_capabilities under meta_key column.

Step 4: The roles are saved in form of serialized PHP array. Change the user role you want to assign to the current user by changing the meta_value as: