Adding text to Membership Registration page

Hello,

On the membership registration page here:

http://www.suspicious0bservers.org/become-member/

We need to add the following text below the text that is there already:

"Payment can also be made by mailing a check to:

ATTN: Ben Davidson
#348
1151 Freeport Road
Pittsburgh, PA 15238

This payment will be applied to a non-recurring membership subscription which will expire at the end of its term. Recurring memberships can be purchased via credit/debit card via PayPal, and the price is locked in for life."

Please tell me how to do this or please do it on our behalf. Thank you, support access is granted.