Installing new gpu to make sli

Hi all!
i have just built new system of 3930k with EVGA gtx460 ssc+ ddr5 1gb DDR5 yesterday with all the drivers and every thing is working smoothly. now i am going to put another gpu MSI gtx460 Hawk(talon attack) 1gb ddr5 in it.
my question is that
should i remove the previous driver of nvidia before installing another gpu?
or should i install it directly and both will work smoothly togather?
or shoud i do what????

both are correct fresh install of drivers or old one also work.
Fit the 2nd gpu boot up the pc and and go to nvidia control panel from there it should enable sli or disable.