95 deviile exhaust problem

I have a leak in the gasket that goes between the converter and the "y" pipe. has anyone had to change this and how easy or hard is it? are the bolt threaded into the cat or are they nutted. Im sure I will break one when I do this. Is there a better fix for this problem or should I go stock????
 
Thanks

I suggest staying stock on a 13 year old car. Use heat to help loosen the threads. These studs will be stubborn.

I have a 96 DeVille, I just replaced mine, NAPA had it for $5.99. I just broke the old bolts off and put 5/16 grade 8's in. it take about 20 min.