I was just wondering....Is scar tissue permanent?

I have scar tissue ( I`m guessing ) in my right pec and hamstring. My right hammy is quite lumpy and always extremely tender after training ( I remember tearing it in basketball training about 4 years ago ) and my right pec can barely stretch without causing major discomfort. Tore that too about 3 years ago doing flat bench with too much weight trying to play with the big boys ( learned my lesson there ) Unfortunately i didn`t do much about it and thought it would heal itself ( fool ).

I was told scar tissue can be healed using deep friction massage, I belive this breaks down the muscle fibres and when healing you`re supposed to stretch constantly making the muscle fibres grow back in their original shape ( long and straight instead of tangled and short ).

Is this possible and would it work on a pec...I can imagine it working on hamstrings but not on a pec for some reason just doesn`t seem right doing it on a pec, this would be an absolute godsend if it could be done.

Anyone ??