how to move marble slabs?
Answers:
A sled and a winch might help you get them up the embankment. I'm assuming you don't want to invest in renting a crane.
You might inquire with local companies that install granite counter tops for kitchens. They will have the proper cutting equipment and the man-power. It might be cheaper to just have them cut it rather than trying to get the equipment. Getting them to go down the embankment might be a challenge though.
Other answers:
carefully
carefully
You can cut the slabs into much smaller sizes. You will need a concrete saw, you can rent them from any rental place that handles tools. They come in 2 styles, walk behind and handheld, either take a 14 inch blade. Be sure to tell the rental person what you are cutting, so they can supply you with the correct blade. Always wear eye and hearing protection when using these saws.
good luck