Your going to have to disassemble the card. Its not that difficult.
Look up tutorials on how to mount GPU water-blocks, that will show all the steps on how to take off the cooler and when your done how to arrange the VRAM/VRM thermal pads. Then just remount the heatsink.
On actual lubricant for the fan, not sure. I think mineral oil is often used for this kind of thing.
EDIT: You will also need some non-conductive thermal paste on hand, as you will need to replace it what was on the GPU. I used Arctic Cooling MX-4 on my 7970.