For checking, you pretty much just have to do it visually. If it looks buggered up it is.
It’s easy enough to remove the trackbar with the tires still on the ground, but depending upon your tools it can be even easier with the drivers side tire is off.
Leaving at least one tire on the ground though, can make it much easier to realign the track bar when you’re putting it back on.
Pull the upper bolt and lower the track bar down so you can take it off of the lower stud.
You may have to use a pry tool to get it out of the frame.
Replace bushings, put it back on in the reverse order.
Not always easy to get the old ones out, but the new ones should go in almost by hand.
Where you run into trouble is with the frame shifting over the suspension. If that happens then when you try to rotate the bar back up into the upper mount it may not align correctly at first.
Having a helper turn the steering wheel slightly will re-shift the frame over the suspension so you can line it up.
Do this with the weight of the vehicle on the suspension though, or you will also have to twist the track bar to get it to line up with the hole.
If you have a lift on it you may have to do this anyway.
One answer to twisting to align the upper bowls holes is to use a really big pipe wrench!