Any advice on removing stuck studs in head?

[worden10 at msn.com (JOHN WORDEN)]

I have some studs in the 16V's head I need to remove and replace.  I have 
tried the PB Blaster, Kroil, heat and even the wax trick with no results.  
My next option is to weld on some of the new nuts and try that, but I figure 
I would ask all of you for some thoughts on this.  Keep in mind before you 
reply that I have tried PB BLaster, Kroil, heat and wax; I am saying this 
because I am bound to get a reply suggesting one or more of these.

Thanks,
John Worden