Heat and peel (slowly). You can pop some hot water in it or use a hairdryer.

Strong alchol on a cloth or papertowel to remove what remains.

If all else fails WD40 also works.

This is from removing labels from cars, where you have to be careful to prevent damage to the paint/clear coat.

With glass you can use a razor to scrape off whatever remains, but mostly it’s not necessary.