At the end I didn't resist and I installed KOReader and Plato with Your simple method. It works perfectly and I enjoy them very much.
May be KOReader will become my favorite engine, it is a very complete system.
Plato has a more simple and elegant interface, has hyphenation and ligatures (Amazon added them after many years, and Kobo has no ligatures in kepub) but it is still young and many features have to be still implemented.
