If by Internal Ram you mean Internal Memory, you can add in up to a 32GB Micro SD card to increase the memory storage from 512mb up to 32.5gb total. I don't believe you can actually modify the physical RAM that's on the smart phone, that's generally something that's soldered into the smart phone's mainboard.
You can however trick the phone into using a Micro SD card as a sort of RAM buffer though, See here. It will not be nearly as efficient as having more RAM on the smart phone though, the SD card will be quite a bit slower in this respect.
