Just copy these: as capitals, Ε Σ, or in lower case, ε σ.
I don't know about Word for PCs, but on a Mac, you go to the Insert Menu, and then to Symbols when the menu drops down, and then select the Greek characters of your choice and insert them using the easy to understand dialog box that pops up. Easier though to copy what I just gave you, and of course, you can change the font, if you want, to match the rest of your text.
Είναι όλα τα ελληνικά μου.
P.S.: Here's another easy way to do what you want. Go to:
Google Translate and choose English to Greek and translate to your heart's content. As a test, copy the Greek phrase I gave you above, paste on the Greek side, translate it to English, and then post your result. If you laugh, you did it right.
Bullseye