Sure there's help! That's what we're here for
What version of JomSocial are you using? Those instructions were written with JomSocial 2.0 (and checked that they work with 2.2 as well). 2.4 did come out last week, and it's possible they changed their template file structure or names.
Also, you're missing the template name above. Usually, the path looks like this (using the 'default' template):
/components/com_community/templates/default/register.index.php
Alex