it doesn't providing you have the tool to retain the the balance shaft timing chain
either the exhaust manifold or drive shaft has to be removed
http://www.lasertools.co.uk/item.aspx?cat=372&item=4258
there is a cover on the timing chain cover where the bolts go through the water pump and onto the cover via the balance chain,
you basically remove each bolt from the water pump side and replace it with a bolt on the timing chain cover side using the tool thus not touching the chain nor timing
don't be fooled this is a nasty job to do