i don't know if there is a guide but i know where these files are
well i use drew's pk2 tools because they are very easy to use
step 1. launch the pk2 extractor and open the media.pk2
step 2. click on extract all (it's a lot of work to extract 521 files)
step 3. go to the media map (it's at the same place as the pk2extractor and pk2editor) and go to interface -> worldmap. All those files are the complete silkroad map:P
step 4. download a ddj converter you can find more info about how it's works at this site
step 5. when you've changed all those files to dds you have to open it with paint.net or photoshop or something like that.
step 6. find the right picture and put the spawn places on the map
step 7. open the pk2 editor open the media.pk2 file and click on select file chose the files that you've edited and import them.
i hope it works^^