Philips Sonicare DiamondClean 9000Rechargeable toothbrush

How do I enable or disable the pressure sensor on my Sonicare?

Can I sync the Sonicare app with the Apple Health app?

How does the pressure sensor feedback work on my Sonicare toothbrush?

What do the symbols on my Sonicare toothbrush mean?

Can I replace the battery of my Sonicare toothbrush?

My brush head is difficult to attach or remove.