This is a long run project. Lot of things were done to achieve a better Start Destroyer. I not intend to build a completely accurate Star Destroyer but it would be closer than the Out of the Box one.
Here they are the main task I planned:
Sand and remove all raised panels and rescribe them.
Trim down side walls because they are too wide and as well as the engine area.
Detailing the hull and side walls
Install the new main and secondary hanger
Install turbo lasers
Install dorsal kit
Install main engines
Add 1/8 styrene sheet on the side hull to extend it