Here is one of the old metal 100 yard markers that I have never really liked.  They were hard to see and needed to be painted several times each year only to look the same the next week.

The replacement process starts by removing the metal marker, which will eventually be recycled at Rainbow Salvage.

I dig in the outline of the granite marker where the old marker was.

 I get the hole to the correct depth and add some sand below the new marker.

 Making sure that it is level and flush with the turf so that the mower won't nick it.

Add some sand around the edges to fill the gap and....voila, the new granite 100 yard marker on #13.  The square patch of sod will be reused in another area.