I did a short day trip to Bethlehm in 2018 as part of my trip to Israel, I'm a big history geek so I wanted to check out the Nativity Church there. It wasn't super straight forward how to get there, but it is possible to go from Jerusalem to Bethlehem on your own, quite cheaply.
- Bus 231 runs pretty frequent service from Jerusalem to the center of Bethlehem every day (7am to 830pm departure from Jerusalem, according to their official time table)
- The bus leaves from just across the street from Damascus Gate. You can't miss it it's a pretty big parking lot with a lot of buses. Here's a link to it on Google Maps.
- Cost was 5 NIS (1 GBP)
- The trip took 50 minutes
- The bus stops in the centre of Bethlehem, here
- The return bus runs exactly the same route in reverse. The last return bus leaves Bethlehem at 750pm every day
- Here's the route's official website that you can see the latest info on. Use Google translate as they don't have a working English version. The site shows you the route and the schedule (note that in Palestine and Israel working week is Sunday-Thursday. Friday and Saturdays are considered weekends; so on the schedule you'll see Sunday-Thursday, then Friday and Saturday schedules)
- Bring your passport. The bus goes through checkpoints and they will ask to see your passport
- From where I got off in Bethlehem, I taxied to the Nativity Church because I was quite short on time before the closing of the Nativity Church. But you can probably walk it if you have google maps or some kind of GPS with you, as it's only a 30-minute walk
I've been told that you can also walk from Jerusalem to Bethlehem in 2-3 hours. But it's not really a nice walk, you'll be walking on the side of a highway the entire time and it's simply too hot most of the year