I am about to get to the change point for the hydro oil on my new Super Z. I plan on using Amsoil 20W-50 synthetic in the hydro system. What is the best way to get all of the old dino oil out of the system? Just remove the drain plug and replace the filter and then refill or drain it and remove filter and then crank and run the system for a few seconds to pump everything out. Will this harm anything or will just draining be sufficient? I understand the Amsoil is compatible with dino oil so if there is some left in the system it should not be a problem. Thanks for any suggestions.