I have had the same cleats for my Shimano clipless pedals in my shoes since I bought my bike about 5 years ago. The shoes are still in pretty good shape but the cleats are awfully worn. (I must be walking the bike too much.) I have also noticed that it is more difficult to "click out" of my pedals. It must be time to replace the cleats.

I bought a Wellgo cleat set for spd pedals because that is what my local bike store had in stock. The hardest part of the installation was removing the old cleats from my shoes. There was 5 years of dirt ground into the bolts and I had to dig it out before my hex wrench would fit. I got the old bolts out, put a little grease on the new ones and installed the new cleats making sure they were nice and tight.

On the first ride I notice a difference. I was clicking in and out of my pedals with ease. The Wellgo cleats work great.