Q: Need explicit instructions on how to eject SD card from slot

"How do I remove a card from the SD card slot?

As with any removable media device, allow any data transfer to SD media to complete before removing the card. When removing the card, the best way to insure the integrity of your data is to drag the icon that represents the card to the Trash, then remove the card from the slot after the icon disappears from your desktop."

http://support.apple.com/kb/HT3553#13

You can right click on the SD card icon on your desktop and choose 'Eject (whatever the name of your card is I here)'

I have the same issue as well and I don't think the people replying have an Imac. I pulled out the card and get a warning, but there is nothing I can find that has the "eject" function listed. I cannot erase the cards either through the IMAC