DIMM Precision Tower 5810

Hello,

I would like to upgrade the RAM for a DELL Precision Tower 5810. It has one CPU, 4 Chassis and dual channel. There are two 4 GB stick in there right now. However, I am not quite sure whether I can add just 2 additional 8 GB sticks in a different channel and if so, where would I have to place it?

Thanks you for your help,