An easy way to replace the artwork location in the gamelist.xml with another / new one is the sed command (stream editor). This example changes the video directory from the relative path ./media/videos/ to the absolute path /mnt/artwork/videos/:
cp gamelist.xml gamelist.xml.backup # make a backup in case something goes wrong
sed -i 's#<video>./media/#<video>/mnt/artwork/#g' gamelist.xml
The part in single quotes does the actual sed-magic:
s(earch)#[old string]#[new string]#g(lobally, i.e. all occurences)
This works for every other path, just change <video> to <image>, <marquee> etc. Omitting the artwork tag before the path will change any occurence in the file, e.g. if the whole artwork is located in another place.
Execute man sed in the command line to get the manpage (manual page) of this tool, or search the web for myriads of examples.
