1. If it's paint handwriting that has been dry for a long time, you can flatten the front end of bamboo and scrape it off, without hurting the glass surface or too much effort.

2. If the handwriting is not self-adhesive, you can wet it with alcohol several times and then wipe it off with a rag.

If the words are engraved on the glass, they can't be removed unless the glass is broken.

4. If it is printed words, you can use wind oil essence or nail polish remover, apply some with cotton swabs, and then wipe it on the printed words with a cloth.