One thing not mentioned is that when jacking up the tractor it will pivot on the front axle.
Having a loader mounted on it and lowering it will keep it from tipping side to side.
If no loader, jack it up and set it on jack stands, leaving the jack in place, but just snug, as a third point, then remove the tires.
If it's a large tire equipped tractor consider using either another tractors loader or a engine hoist to lift the tire and hold it, they get real heavy when they get off center.
I have seen the aftermath of several owners that have jacked up their tractors in the center, pull a tire off and have the tractor violently flip to the other side, some even coming off the jack and crashing to the ground.
And like others have said, Sometimes it's just easier and safer to take the whole tractor in and have them load the tires.