I use disposable stakes and made a puller that ought to work on rebar stakes as well. It looks kind of like the one in this video.

Video should start at the point where he is pulling the stake, but if it doesn't it's at 4:52

https://youtu.be/DumdIAlf2U8?list=PLt8YfIV3SgNQMy2_f8Ep42qR-Y1CyrsJd&t=292