How do I disable several Pstones. like Jack-o-Death while keeping others?

Also how do I remove the option of Godstones repairing armour but still make them heal you?

1. Remove their definition from the force-field-flag section in the config
2. Modify their definition in the force-field-flag section of the config.

Read the OP and the wiki, this is a question you wouldn't be asking if you had. I wrote this stuff so that I wouldn't have to be answering supremely basic questions such as this.

http://dev.bukkit.org/server-mods/preciousstones/#w-field-flags
http://wiki.sacredlabyrinth.net/index.php/PreciousStones#Field_Flags

But when i restart the server they all just come back in default form :S?

That is because you are making mistakes, you are leaving spaces where you shouldn't, or you are using tabs (which you shouldn't use in yml files), etc.

Yml files are very picky, everything has to be exact. Make small changes at a time and restart to make sure you didn't make a mistake.

Okay thanks, will try this now

Thanks but I don't understand it so I wouldn't know even if I read it...

You do know what a list looks like in the config no? Look for the list called force-field-blocks, it has sections of flags, each section corresponds to one of the default fields, you can tell them apart because each section starts with a "-", and the first flag in each section is called "Title" that has the title of the field.

You can remove the sections of the fields you don't want.