I installed these right away when I got a new Fender Jazz Bass, and had no difficulty simply removing the original strap hooks and replacing them with these.  The screws went in easily, with no need to re-drill or anything, although I think they tapped in further than the original holes were.  They feel tight and secure.  The hardest part was getting the top buttons locked onto my strap, which has some padding.  Took some finesse to get the locking ring to snap in just right, but once I did they were perfect and I'm now confident that the strap is not coming off unless I want it to.  Rock solid--a classic product.