'Minimum refferals to use custom avatar hack' problem

I installed the 'Minimum refferals to use custom avatar hack' but im not sure how to actually give a user a referral??? Can neone tell me how?

[Gary King]

Tell your members to go to the following link to view their referrals link, and when someone visits that link and registers, whoever's link that belongs to, their referrals count will go up by one.

http://www.your.site/forum/misc.php?s=&action=faq&page=2#referrals