[Dave in MN]

" should I remove the remaining nine studs, I plan to but what should be the gentlest way to go about this? "

Try this: Heat the stud to cherry red as close to the the base of the stud as possible without damaging the block. There is no need to get the whole stud red, just the base near the block. At this point give the top of the stud a good rap or two with a 16 oz. hammer (straight down). As the stud cools press a candle or stick of paraffin canning wax against the stud. At first, the paraffin will go up in smoke but when the stud is at the proper temp, it will accept some wax which will run down the stud and follow the threads into the block. The wax will lubricate the threads and the stud will usually back right out with a stud removal tool. Occasionally I have had to repeat the process a second time to free a stubborn stud. I have only broken one stud since an "A" friend gave me this tip.
Good Day!
Dave in MN