I got these to replace the cheap plastic pins on a Epiphone acoustic. Installing them was no problem, just the same as if you were changing stings but with the addition of changing the pins. I will say one thing. The resaon I got these was because the original pins wouldn't keep the strings in plaace anymore. I thought upgrading the pins would solve this, but turns out the problem was in the holes of the bridge being worn out. If you, like me, thought that new pins is the answer to this, then you might want to check the state of your bridge first.
As for the quality of these pins, they look and feel very classy. I can't say if they improved the tone or the sustain of the guitar, but it probably did to some extent.
All in all a nice, inexpensive upgrade. I would reccomend this product.