Can you tell me is kidney stone removal hurtful?

Yes it can be painfu: Most kidney stones 5mm or less will pass on its own but it is always painful as they pass through the ureters into bladder and than from bladder through urethra larger stones may or may not pass and have to be either broken down by lithodystrophy or surgery kidney stones are painful and till these are passed or removed you need strong pain meds.

Yes, some but ...: Nothing is free and always comes with a price; so is stone removal. Largely, the pain related with kidney stone removal is manageable and can be well managed with understanding reality and judicious use of pain medication; not bad.

Anesthesia: Stone surgeries are typically done under anesthesia so you should be comfortable. Of course the location and size of the stone make an impact in your overall recovery. You should do well.