As one could expect, I am not the first to convert the Tamiya 1/16 Leopard 2A6 into a Leopard 2A5 DK. I found a build log in German here: http://forum.axels-modellbau-shop.de/thread.php?threadid=245&threadview=0&hilight=&hilightuser=0&page=1. Excellent result he achieved I would say. Also very interesting and informative build log to study.
I am thinking of starting out by just building the tank as stock and keep from obstructing the conversion. For instance the L55 gun barrel shall never be installed. Instead I should immediately mount the L44 gun barrel.
This would be a way forward as I would get to know the tank before I break it apart.