How do I get classical greek to work in Ubuntu?

I am using LaTeX to write academic books and papers, and I need to write some things in classical Greek. The material will be citations from authors who wrote classical Greek (the authors will, actually, be 16th century humanists). I use vim to write things in. I have found keyboard layouts, and fonts, but what I am having a lot of trouble with is getting these things to actually work: I can get Greek letters OK, but I really need the accents. I cannot find out how to type the accents, whatever I do. I am not a novice in LaTeX, but this has got me defeated. Also the documentation for this doesn't seem to fit together: there are lots of helpful things on installing languages ("language" here means system-wide abstraction) and lots of helpful things on installing fonts and keyboard layouts, but actually installing a language and a keyboard layout AND MAKING THEM COMPATIBLE WITH EACH OTHER seems to be the tricky bit.

Also (and this is a very significant gap): the only dialect of Greek you can install is called "Modern Greek". This is the only version of Greek that I have ever seen in these configuration dialogues. Well, ancient Greek is important to quite a lot of people.

Solution 1:

If you install the ibus-m17n package, log out, and log in again, you'll get access to a Greek, Ancient (...mizuochi (m17n)) input method.

Solution 2:

In most Greek keyboards you use the right side Alt + "alphanumeric key", and for some characters right Alt + Shift + "alphanumeric key"...

NB: Keep in mind that it is the right Alt key and not the left one.