!!! If not other stated, the decals are for the inside mounting of windows !!!
Step 1: dip the decal for about 30 seconds in lukewarm water
Step 2: place decal + backing paper on the window (paper down on surface)
Step 3: gently press the decal on on one side and pull out the backing paper on the other side. If required you can adjust the decal now
Step 4: smooth down the decal with the greasy side of the backing paper
Step 5: gently press the decal on on one side and carefully squeeze out any remaining air bubbles and surplus water with a squeegee, creditcard or the like
Step 6: wipe away remaining water from the decal and window with a paper towel
Step 7: let dry 24 hours. After drying you can clean the window as before however don´t use any sharp or raw items for it