I'd like to see your breaker bar.
When we do it we have one man on the brakes and two on a 3/4" 4 foot breaker bar and then it will loosen. I'm not sure how big a boy you are but the other Porsche tech and I are just over 200lbs. That's a lot of weight and a lot of force to break that loose. Also the wheel has to be off the ground when loosening and tightening per Porsche. Sure seems like a lot of work and some risk to someone who isn't fimilar with CL's for a vehicle that is that expensive yet the labor will not be much at all at a dealership. Maybe 1 hour labor? That's a guess without checking online to see what it pays.

 

And before somebody asks,
no you cannot use an impact.

 

Sorry. I can do it with my torque to correct eight with my daughter pushing brakes. I'm at 200 lbs. I have the same torque as all techs. I'm just a stud. Not.