I did law school evenings, while working full time. Really it is about time management. You can't have wasted time. Think about what you can get done during your commute. Are there times during the work day that allow for studying? I got a 30 minute lunch and two 15 minute breaks. Are there aspects of your work when you can multitask? While some of my work is really intellectually demanding, other parts are mind-numbingly tedious.

I read during my commute (train). I did homework during my lunch. I listened to downloaded review materials while doing any repetitive or low-mind-capacity tasks.

I used one full weekend day for school work. I took one full weekend day off from work/school to help prevent burnout. I was still pretty burnt out by the end. I got pretty respectable grades (top quarter of my class), but was surprised that even though it was a part time program, many students weren't employed outside of school. Be prepared to compete with people who have a LOT more time than you.