Hi,
http://www.cic.gc.ca/english/department/atip/requests-atip.asp
For the GCMS notes Sponsor will need to order thru this website
Note that the sponsor and principal applicant will need to fill up an authorization form (IMM 5475) where the principal applicant authorizes the sponsor to request for information on his behalf. Sponsor will be charged CAD 5.00 for this which is fairly cheap. You will promptly get the notes a month after the request provided the information you shared is correct.
Hope this helps!