How do I disconnect the battery in a 2010 Kia Soul?

My tire pressure light came on when the weather got really cold and I need to reset it. How do I disconnect the battery in my Soul? I know this is probably a stupid question, but I'm a girl and not very good with cars. I did this before on a Ford Ranger truck and it was easily disconnected by unscrewing the terminals. However, when I tried this on my Soul last night, the positive one wouldn't come off after I unscrewed it. Thanks in advance!