Custom text on a page

[MJJOS]

Hello,

On my forum I have it set that a user must activate their account by email. On the page that comes up after you fill in the details and click I agree for the registration agreement,  that says to check your email for an activation link, I want to add a piece of text along with whats already there, regarding the email they will get. How would I go about doing this?

Thanks!

MJJOS.