I might as well try them out
Now, guys... install is REALLY tough here. You gotta take off the glass
If you'll notice the decals and magnets cover the little rubber bumpers. That means you have to remove them first. The install the magnet or decal and use a sharp knife to cut the hole out if you want to reinstall the bumpers. I recommend wetting them and sort of pushing and twisting them back into place. We didn't cut these out since the original decals on the aprons might not be perfectly aligned so you can adjust your decal to cover properly and then trim the hole.
The decal could be installed dry or wet, your preference. If you are pretty confident in your alignment skills just pull back some of the backing and then do the alignment with part of the decal before you pull the rest off. In my experience the crucial part is the top angle that borders the playfield and the screen side. The rest falls into place.