First, make sure you've copied the photos to your SD card if they haven't been set to go there automatically. Then, you'll need to put the micro SD card in the adapter card and put it into the card reader on the left side of your Mac. Go to the "Go" menu and select computer, then locate the SD card icon. Open it, and find the folder that says something along the lines of "my pics" or something of the sorts. Your picture files should all be there. Just select the ones you want on your computer, then copy and paste them to the desired folder. And that's it!