The good morning often is a cause for concern but in reality if you're a healthy lifter with no prior injuries, you should be able to perform them fairly safely.
One thing thats great about the move is that max torque is applied at the hip at 90 degrees. Which is different than say from a horizontal back extension where torque is applied at 180 degrees at lockout. So varying the angles at which you load the hips is of vital importance to improve both an aesthetic goal and a performance based one.
It's a giant hip hinge with the barbell on your back!
1. Set the bar on your back like you would on a back squat.
2. Stand up with the bar and step back. Shoulder blades tight, brace the core, etc.
3. Taking a soft knee bend and bracing your midsection, push your hips back. Drive the hips back to a standing position. Repeat for reps.
Tip: How far down you go will be dictated by how mobile your hamstrings and back allow you to go and how much you can control the movement. Load-wise you want to stay fairly light as it is an accessory movement.