I know this is not an original idea, but there are two questions that need to be asked: which actors would play who and how would it look?
How to make a Beatles Biopic
First question (easiest): "How would it look?" Well, I think personally it should be a series. A friend of mine named batsonjacksont (you all know him) created a Michael Jackson biopic concept. Basically, the seasons covered a decade, and everything that happened in the decade was covered. Here's the problem with that format: The Beatles were actually together for (including Hamburg years and pre-Beatlemania) 10 years, one single decade. So how would we split the seasons? I had an idea: a lot of stuff happened in one year for The Beatles meaning there was more stuff that would be covered in a few years/one season. Probably about the same amount of stuff which was fit into batsonjacksont's MJ biopic's seasons.