I emailed them & got a quick response. We thought it would be challenging to install especially given the decal is rolled up tightly but if you wet the glass surface generously, itís quick & easy. Got it done correctly our first try. Unfortunately, the addl corner decals we ordered didnít come w/all 4 corners even though thatís what the picture shows. You only get 2 corner pieces so need to order a qty of 2 if you want to do all 4 corners.