I ordered a set of TruGlo TFO sights a week or two before Christmas from Walmart.com for about $70. They were a stocking stuffer for me...lol
I installed these the other day. Stock rear sight was super easy to remove, just loosen set screw and it slid right off. My front sight wasn't pinned and I don't even have a hole in the slide for a pin. I bought my LC9s in early August. The front sight wasn't super tight, I used a nylon punch and a small tack hammer with the pistol just lying on my leg, not in a vice.
The new front sight went in the same way, while the rear sight was very tight and I needed to file on the bottom a bit till I got it to start pushing into the dovetail very firmly by hand. A drop of blue threadlocker on the set screw and then snugged up firm.