dissamble front block remove ram and your 5 way, remove front block from gun. take your front block put it in a table vise out in your garage, but first wrap your front block extremly well(I prefer a good thick sock) put a heat lamp on the assembly for 10-15 min. Take a wrench place on the back end of rock(like you were going to remove it) brace it and secure it, now get out a pair of vice grips lock them as tight as you can on the knob, take a hammer tap the vise grips, gradually tapping harder(viberation is the goal) then strike very hard, should destroy lock tight. I have never had this problem but have removed lots of red lock tighted rams, 3 ways and regulators from the front block in this manner.
let me know if I can be of further assistance