Couple of ways to approach JerrahWorld from Austin:
First caveat: Do NOT go to Downtown Dallas. 70% of the traffic will be arriving at the game along I-30 from both Dallas and Ft. Worth (Note: traffic from the North (plano, etc) gets dumped onto I-30 east of the stadium).
Route 1: I-35 to Waxahachie. Exit US 287 towards Ft. Worth. State Highway 360 intersects 287 west of Midlothian, which goes north. It becomes a freeway in Arlington, take it past I-20 to Division Street. Exit Division and head west. You won't miss the stadium.
Route 2: I-35W towards Ft. Worth at the split in Hillsboro. Take I-20 East to Arlington. Exit Collins Street, head north to Stadium.
I agree that leaving at 2 pm is cutting it a little close considering game traffic and parking. I'd say give yourself an extra hour and leave at 1 pm and you should be fine.
Of course the proper time to leave would be 8 am so you leave about 6 hours for tailgating.