There isn't a good way. There are lots of different techniques that will get you partway there, but the end result often isn't particularly good.

A better solution might be to start from a height field such as a Lunar DEM. http://imbrium.mit.edu/LOLA.html looks to be the master archive from the Lunar Orbital Laser Altimeter (LOLA). Resolution is likely to be an issue, but that's also true with trying to do shape from shading (which is a good search term for the type of question you're asking).