Hey there,

You can copy the default.php file from its original location which is at JoomlaFolder/components/com_easydiscuss/themes/wireframe/profile/default.php and paste it at its template override location which is at JoomlaFolder/templates/yourCurrentTemplate/html/com_easydiscuss/profile/default.php.

After that, you can do your customization at the default.php file which is at its template override location so that it won't be overridden back when you update to the next version of EasyDiscuss.