1) That chip isn't locked. The only way to overclock is by changing the BLCK - doing this can and will fry your entire motherboard.
2) NEVER use a program to overclock your CPU, and never let a motherboard do it for you. They have a nasty tendency to over-volt, which will again, fry your computer.
3) You need an aftermarket heatsink to overclock, since overclocking produces more heat than normal.
That being said, if you do overclock in the future, do a LOT of research first. It's a delicate process that requires finesse - if you go in there willy-nilly, you're going to break your entire computer.