I'm 32 and going back to school this year. It's been really hard because I have to juggle work and school, and because I got so used to being an adult in charge of my schedule and my life and I find it very difficult to sit exams and get grades and be judged on my performances.
I don't have a magic formula, I find focusing on the goal helps a lot, and having a good support network around me. I try to set aside time to study but it's really hard - housework, actual paying work, bills... It all takes so much time !