Will hasten to had I haven't had a chance to try this with live rounds yet, so undertake at your own risk
Short version...
Remove butt stock bolt and springs minding eyes face ornaments etc
Take the smaller spring out, but the big spring back. Screw back together.
Results as follows. ..
Standard double spring combo takes 13kg of force to cock/extract
Single spring brings it down to a pleasant 8kg
Never taken that spring out have you ? tongueout I did it once and spent an hour trying to get it all back in again.
Not sure it's for me, if anything I want more force as I've noticed that the bolt doesn't always go into battery on mine. I do know someone with a para FAL who has done something with the spring in his, not sure what he did tbh.
As mentioned before, using homeloads or GGG seems to be the cure for my particular one. Both work fine but MEN, RG, R1M1, Norinco, PPU etc forget it.
The above post probably contains sarcasm or some other form of attempted wit, please don't take it to heart.