What you could of done was just layered it right in shop leave first layer on backer, juice up first and second layer sides real good I use water-cheap- maybe one drop of dawn dish wash and slide your decal right in position. Go head and take transfer off,vinyl sticks real good vinyl to vinyl and let dry about 5 min,. don't want the backer to the get to soaked.Just repeat on last layer.If any bubbles, you can get rid of them as you do each layer.If you don't have any good squeegees make sure they are straight and wrap a paper towel around it and keep your vinyl wet you will have less scratches. You can go to Hardware, Dollar store and get velcro smooth piece and stick on them on, just cut to size. Works better than the ones you buy That what I do to all my small decals.Get to glass the decal is so thick you can put on dry or just very little water. Some like to do it on location, I hate all that sliding on glass.Seems like the water doesn't like to dry behind the vinyl on glass.