Basically a split occurs when the clutch needs to be changed. Sometimes other part need to be changed too. breaking the tractor from front to back is the split!
Welcome aboard!
I'm no mechanic but I split my Ford 1210. It was easy because it isn't a big tractor but the basics are the same. Removed unnecessary things that would get in the way - in my case that was hood, fuel tank and battery. Then remove or disconnect anything that crossed the joint of the engine block/bell housing. Several wires and hydraulic lines. Support both halves of the tractor. I used a cable come-a-long from an overhead attachment point for the front and made a "kickstand" for the back half. Then removed the bell housing bolts and wiggle/pry it apart.
A lot of variables would be the determining factor of expense. Size of machine, for sure. Is the machine being sent to a repair shop or doing yourself?
If you are mechanically inclined at all separating a tractor is not a big deal. You disconnect anything that restricts removing the engine from the transmission. Be aware of some safety practices, like blocking the tires, wedges on the sides of some engines, proper jacks, patience. Oh, maybe a good coach or two, and the internet!