Upload extract this .zip file on your root directory where you install elgg.

Activate plugin

change pages/join/index.php of plugin and add your own description add this line  to your page where you want to view join page

if any error configure manually by given method- 1.Copy views folder of plugin directory to default views directory 2.edit pages/index.php of join plugin or copy <?php echo elgg_view('core/account/join');?> code where you want to view register box.

i am not a elgg developer but i have developed it for my Social Portal www.dostsabha.com