What should I do if I run out of time on the PSAT?

Omgz Im in tenth grade and im taking a PSAT tomorrow too. Im nervous by the fact that its timed. ...I always like to take my time.. :( Im just gonna study as much as i can today because they gave a practice test to take home and Im gonna try my best. Its 25 minutes for each part i think... and 30 for the last one... AAhhh this is stressing. Your not alone though;) I wish u the best of luck.