Here's how to get the job done without discomfort or injury.
Wear a dust mask, goggles, work gloves, a long-sleeve shirt, and long pants to protect your lungs, eyes, and skin from fibers.
Don't stand on the joists. If you lose your balance, you could crash through the ceiling. Use a piece of plywood or a couple of sturdy, wide boards as a standing surface, and move them around as you work. They must span at least three joists for stability.
Illuminate dark corners of the attic using portable battery-operated lanterns or clip-on workshop lights.