As you can see, our intercooler provided an obstruction when we opened the petcock, but we solved the problem by using a plastic scraper to redirect the fluid. The switch to a waterless coolant requires you to get all of the old antifreeze out of the system, and ECS recommends removing the block drain plugs to do this. The drain plugs are Allen-head bolts located toward the bottom and back of the block. Ours were not cooperative, so you'll probably need to heat them up with some sort of torch. Since we didn't have access to one, we removed the water pump and used compressed air to force out the remainder of the fluid. Using a small hand-held propane unit might get the job done but frankly, we didn't think of that until later. Evans Cooling also recommends flushing the system (prior to draining) with its Prep Fluid.