3
just be carefull not to overwrite modules if you use new release of them (ex : news 1.3 series instead of 1.1 series,this last one was incorporated in 2.0.x series, not anymore now). Take care of you mainfile too.
Another way is just to apply 2.0.13.1 full on 2.0.9.3 (without mainfile and eventually some modules you don't use).
marco
Do synergy or die.