Do I need to remove & service integrated headset bearings when replacing fork?
If your headset bearings are cartridge - in a sealed unit as opposed to exposed ball bearings held loosely in a cage. The cleaning and re-greasing of the bearings  does not apply to you.

Although it is also known for some people to remove the seal over their sealed cartridge bearings - to clean and re-grease and then pop the seal back over them.

But generally - you don't need to do this.