[Building Sakai] Realm and Role problem

[Khan]

In site.templete  I created a role "customStudent", 
then I created about 100 project sites,
and in each site I assigned role customStudent to students.
 
Now I want changes in righs (permissions or functions) of users having role "customStudent"
 
Should I go to each and every project site and edit the realm role, or any otherway so that if I do change and then it is propageted in all sites.
 
please suggest a way so that in future I may not face same problem.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://collab.sakaiproject.org/pipermail/sakai-dev/attachments/20111021/27e261f2/attachment.html