Change Register and Forgot Password links

Dear friends,

I have two drupal 6.x installations at http://www.vshiksha.com and http://cbse.vshiksha.com

I want single user base and single signon for these two installations. Both of these installations are using different databases.

I have installed Site Network module for this and made www.vshiksha.com as server and cbse.vshiksha.com as client. It is working fine. But users in the CBSE section are still presented with the Register and forgot password link, through which, they can register in this section, thus again creating two different user repositories.

What I require is a method to change the Register and Forgot Password links to the user section of main website, so that users are created at one place.

Please someone help me out!

Regards
Satya Prakash Shukla