How do you spell newspaper in greek English?

There isn't a single, universally accepted "Greek English" spelling of newspaper. Greek doesn't use the English alphabet. If you want to transliterate "newspaper" into Greek letters using a standard system, you'd get something like:

* νιούσπεϊπερ (niouspeiper): This uses a fairly straightforward transliteration, approximating the English pronunciation with Greek letters.

However, this isn't really "Greek English." It's just a transliteration of an English word into the Greek alphabet. There's no such thing as a distinct "Greek English" language.