Check that the decal sticks to the transfer tape (see picture), not the waxy backing paper. If it doesn’t, place the decal (clear side up) on a smooth flat surface such as a table. Take a credit card and rub firmly across the entire decal. Start from the center and work out to the edges.
Clean the surface thoroughly with alcohol or water and dry thoroughly. Don’t use Windex or similar as it will leave residue on the glass and prevent the sticker from adhering properly.
Place the sticker on the desired area, level and center it. Use masking tape or scotch tape as a hinge to secure the decal (either at the top, bottom or either side).
The decal will stick onto the transfer tape. If it doesn’t, place the decal back onto the backing paper and rub it in place firmly with a credit card. Peel off again carefully.
Completely remove the backing paper off.
Rub the decal with a credit card or equivalent.
Start pulling from any corner at a tight angle across the vinyl decal. Be careful not to pull the sticker off the surface. If that happens, gently press the decal down onto the surface using your fingers or use the transfer tape and rub with the credit card as in Step 4.