Is it possible to remove and clean fuel injectors yourself ? Or are they taken apart and rebuilt when you send them back. I'm new to the diesel engine family and have never pulled a fuel injector to have a look see. I know its probably best to leave well enough alone but I would like to know more about my engine. After a glow plug problem I changed out 3 plugs and got such good results it makes me wonder what clean injectors would do.

You can send them out to a local shop for cleaning and calibration.
I found that this was just an unnecessary expense.
Yes you can clean the injectors yourself. They can be removed, taken apart, cleaned and reassembled. I would replace the metal seal (washer) under each injector. I used some carburetor cleaner. Make sure you torque everything.
After I reinstalled them I used a product called “lubro-moly”. Simply crack open a can and let your diesel slurp it up! (Follow the directions of course!).
Actually the “lubro–moly” treatment is all I ever use, once a year.
Do a search on this board and there is plenty of good info here.
-Anthony