Use time traveller's mini tweaker to edit scene.dat, you can edit either file, if you edit the one in your sh3 folder the changes will reflect inmediatly, if you edit the one in the mods folder you must disable and then reenable the mod for the changes to take effect. Also remember that you need to exit sh3 and then restart it to enable the changes, if you just exit the mission/patrol it doesn't work because sh3 preloads most files at startup.
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