Right. Just started. How do I convert my videos so I can watch offline

I have enrolled with Kaplan (Blended Enhanced).

I have considered the advice here and I have decided the best way for me to do this is to watch the videos for each study session, taking notes on key concepts, and immediately doing questions.

Question is, how do I convert these videos so I can watch them offline in my commutes/ flights?

I have a macbook and I also have my work laptop which is Windows based. I probably prefer to use the windows laptop so I dont have to carry two with me when I travel.

Any advice?

Not a computer geek, so please bare with me in your explanation.