From a quick look , what I found is you can NOT upgrade the video card in that laptop. The specs shown
here meet the minimum requirements but you'd would have to turn EVERYTHING down to the minimums to even get it to run.
When the game starts click on video settings and lower the texture size to the lowest. Then in game once you get it started go to the graphics setting and turn off and lower everything in there.
The game will look like crap and even on the lowest setting may not play it very well. To be sure your card is being used for the game right click the desk top, select the Nvidia settings and under managing 3d be sure AH is set to run with the better video. Also when starting the game be sure in the video settings show the Nvidia card as well.
The bad news is unless you buy a "gamers" laptop designed for gaming your going to be disappointed in the performance a laptop will give you.
Good luck