1) Begin by Signing into thechurchofjesuschrist.org (top left image).  2) Once you've signed in, select "Patriarchal Blessing" from the drop down menu in the upper right hand corner of the web page (top right image).  3) Follow the link "Family Blessings" (bottom left image).  4) select the "Request Family Blessing" button (bottom right image).  5) You will then need to fill in the information requested (you'll need the ancestor's full name as well as Date of Birth and Date of Death (You cannot request a patriarchal blessing of a family member who is living).