Filling/shaving riser blocks? Options

[PegGTS]

Just wondering what the easiest way of removing the letters on the riser block replicas is. Filling in the letters with bondo/body filler? Or is it possible to sand them all the way down? Anybody know how to go about this?

[underground_desi...]

Watch some videos, ask a friend who works in the same field.

Try not to fill the hole, but rather make an island around it and slowly try to smooth everything out. Looks like you will be adding bondo to the whole "face".
Start with smaller batches so you don't waste it when it dries up, it happens pretty fast depending on temperature.
Look for a good brand too, something already tested and know for quality.

When you start sanding, there is a slight layer of wax or whatever on top, that thing gets your sand paper clogged up. Maybe buy a mesh type sandpaper and take off the layer, then proceed with normal one.

this is it.