How to disable a plugin manually?

[polyfragmented]

hmm...did you mess with template file or template functions ?
Try to overwrite them with a backup file (disable by renaming or deleting functions.php temporarily).

No messing with template or template functions.

Of course you got rid of all calls for contact plugin in created pages ?

I had no chance to put any calls anywhere, the accidental deletion happened soon after I'd put the plugin files into the plugins folder.

Can you rename /data/pages to something else, and create a new /pages directory ?

Yes, but doesn't do anything noticeable except cause 404 errors, heh.