There is no step-by-step guide, none planned, none intended. dfWorldTinker's use is self evident to the scarred, !burned!, maimed, mutated, battle-hardened wretches called "DF modders".
When I get world.dat documentation, you get documentation. Until then, I will be preoccupied with reverse-engineering world.save file.
This is a low-level, direct edit of your savegame. No training wheels. It is really targeted at people who have a pretty solid foundation for modding DF, understand DF's file system structure, and already understand how to tinker raws with DF's settings, data files, etc, but want the ability to tinker without genning a new world. It lets you slice at your save with a scalpel or hack at it with a Battle Axe, as you like.
Based on Voldine's first post, I'll assume his intended purpose is to mod the raws to add something (workshop? material?), then sync them into an existing embark.
First of all, make sure that DF savegame compression is turned off. If it was not, you will have to change the setting, open the embark, resave. If you don't know what «init.txt» is, then go research it in the forums and on
MagmaWiki.
Then, edit the raws of the savegame. Not the DF raws, the savegame raws. There is no validation. If you make a mistake, only DF can tell you. Tersely. The DF world save file stores the object tags of entries in the raw file, but does not store the entire contents of the raws. DFWorldTinker lets you get around this limitation, by injecting new tags into the world save file, so that DF will load their full data from the savegame raws which corresponds to the savegame. If this is sounds like the gnomish gibberish, consult
MagmaWiki.
Run dfworldtinker from the DF folder. The interactive menu is simple; enter the region folder's name or number, then the «sync» command, then follow instructions.
Status will scroll by the screen, showing any new tags that were added. Once a tag is added to a savegame, it is impractical to ever remove it. The game world file will automatically be backed up (name given by the program), so that you can manually restore. Keep in mind that any bugs introduced by editing the raw files will naturally require restoring those independently.
In short, this is a
Hole Hawg style tool.
(excerpt from IN THE BEGINNING WAS THE COMMAND LINE)