There is paid parking available in the lot directly outside the stadium entrance and also nearby along East Mall. If both of these are full, you can backtrack to the east and try either parking on Westbrook Mall itself, or at Thunderbird Parkade, which is at the intersection of Westbrook Mall and Thunderbird Boulevard.
On the UBC map, the stadium is designated by a red arrow, and a P designates the parking lot at the entrance to the stadium. Thunderbird Parkade is the blue rectangle up (north) and to the right (east).
Note: the campus police are VERY diligent about enforcing the parking regulations, so make sure you put enough money in the meter!
Address: 6288 Stadium Road, Vancouver, BC
Directions to the stadium can be found here.