how to erase education stamp?

You can't erase the educational "banner".  There are a couple of ways to make it go away though.  A simple Internet search will give you the answer you're looking for.Next time, don't hijack a thread started by someone else on a totally different topic.  That's just not good form.

See the Related tip 9757 - one of the benefits of using individual (not hijacked) forum topics...