You don't need Sabre specifics...
You just need to know the best way to plumb it on your boat. It ain't rocket science...
As I'm sure you already know, the Great Lakes are "no discharge" waters, so the only legal setup is toilet to tank, tank to pumpout fitting. So if your boat was delivered to a Great Lakes dealer by Sabre, there may not be any overboard discharge thru-hulls. So the first think you need to do is hunt for any that would allow the toilet to flush directly overboard or dump a tank. If there are none, you'll have to install at least one that will do both.
After that it's simple: Install a y-valve in the pumpout line. One side to the deck pumpout fitting, the other side to the macerator pump--which should be mounted above the tank. A 1" line from the macerator to the thru-hull...you're done.
If you want to have the most trouble-free installation possible, go with a Whale y-valve...do NOT go with Jabsco. Good quality y-valves have a "barrel" inside that rotates to open one side or the other...the Jabsco has only a flimsy "gate" that the lever swings to block one side or the other. I've seen a grape seed jam it and I've never seen one more than two years old that didn't leak. Return the macerator and buy a SeaLand T-Series "Sanipump"...it's an electric diaphragm pump that can run dry without harm and will last forever.
If you have to install a thru-hull, locate it where it can do double duty as both a direct discharge for the toilet and a tank overboard discharge.
And while you're at it, upgrade the toilet to a Raritan PH II or PHC and reroute your head intake line to tee it into your head sink drain line, which will provide a safe source of clean fresh water to rinse sea water out of the system before it can stagnate and stink.
And then consider joining the Sabre email list...which is a Yahoo group.