Not familiar with Goldberg in particular but there are three common decal types.

Water-slide

Die-cut self-adhesive

Uncut self-adhesive

Snip off a corner of the sheet and try to seperate the decal from the backing with the edge of an X-acto knife or razor. If that doesn't work soak the test piece in water and see if the backing absorbs the water and the decal covering slides off after 60 seconds or so.