I would assume that if you're driving a Skyline, emissions and environmental concern may not be on your top list of priorities, especially if you're building a car for the track and race purposes. Removing this component can rarely cause a car to fail emissions testing, so I recommend keeping everything, just in case in the future you need to re-install it to pass emissions testing. Removing this system doesn't harm the engine in anyway at all. Pictured below, it's the black round canister bolted to the rad support, just under the AC hard line and in front of the power steering pump.
There's going to be a number of vacuum lines coming from this thing, the procedure is quite simple really; Start by tracing back the rubber vacuum lines as fast possible, cut the rubber lines, put a plug in them and secure each plug with a hose clamp.
The picture below, has the canister removed, you can see the rubber line near the front of the frame rail that now goes into the hole at the frame. If you're curious how the engine bay looks like it's barely dirty, this was right in the middle of a major Engine Bay Clean up I did to make it shine.