How to insert DOI to APA output style?

I’m using APA 6th revised with no initials and I need to include the DOI numbers in the bibliography. Could you please provide clear, step by step instructions? I’m working from rural Africa with intermittent internet. Thanks

http://community.thomsonreuters.com/t5/EndNote-Styles-Filters-and/How-to-insert-DOI-to-APA-output-style/m-p/136808#M13975

repeated question see above for link to the one with responses.