My friend Todd let me shot his FAL while i helped him moved and I loved it and got a stiffy after the first 3 rounds. The only thing I didn't liked was the stock pad and the sights. Sights are easy to change, but recoil pad idk.Can i change it out with a limbsaver? I figured between that, a tuned gas system, and possibly a comp will make it shoot a lot softer.

Since nobody has weighed in yet, I'll take a stab at it.
The critical question is whether the length of pull is correct for you. There is some variability to FAL buttstock length (Israeli Light Barrel is the shortest, IIRC), and the common metric plastic stocks have a raised section in the center that cannot be simply ground off, meaning that a typical limbsaver-type recoil pad cannot be installed without some work.

If the existing plastic stock has the correct LOP for you, you are going to be limited in pad thickness.
Basically, you get the Pachmayr Decelerator Junior pad that's solid all the way through, and attach it to the steel buttplate for a G-1 or Israeli light barrel stock. Drill a hole in the center of the pad for the center screw that attaches the buttplate/recoil pad to the buttstock. It won't fit flush around the perimeter, so you'll need to fill that gap with epoxy or some such.  

Since I don't know which version FAL your friend has, I have to say there are many "stock, factory pads", ranging from the metal pads originally used by both the L1A1 (Inch) and G1 (metric), to the Imbel and SA (I think) which had rubber buttpads.  There are US-made counterparts that also have the rubber pads.  These rubber buttpads  are mated pieces to the buttstock, and because of design details, it's not easy to adapt a Limbsaver to a FAL stock.  Besides, IME, the rubber buttpad really reduces the recoil, as compared to the metal versions.  But felt recoil is subjective.

It's also important to remember your application.  Are you buying the rifle?  Adapting a new buttpad is probably an owner-type decision.  If you're just borrowing it, you can buy a Limbsaver slip-on, but watch out for your Length of Pull, aka LOP.  Some FALs already have awkwardly long stocks, and adding another inch or inch and a half just negates the comfort and accuracy you thought a recoil pad would bring.

If you are buying the rifle, and the buttpad is the potential deal breaker, I suggest you first understand the rifle design (a good thing if you're the future owner) and check out what's available out there in terms of  stocks and pads and LOP.  You'll make a better informed decision.

Rubber buttpad, the right gas setting (that's another thread) and a good brake (I like Entreprise Zero Climb) should be all one needs.

Good luck and let us know what happens!