Many of us know of this book. The only place I can see to obtaining it is through a Japanese auction site. (Which can be done in cooperation with a domestic bidding partner who's name I don't know offhand; this was something Tim found.)
Anyway,
very little of Japanese specific El-Hazard material has been translated by ANYBODY. About the only thing I've ever seen translated was the radio drama, and that was in summarization, not word-for-word.
Local site member MrWhat is a beginner in the Japanese language and has currently translated a couple songs and some assorted other things. (See the Conqueror Jinnai song in this forum for a result of that work.)
While it'd be very interesting to get entire books translated, that's a major undertaking and you're not likely to see anyone do it [for free] for quite a while. I know for sure that the many books, dramas, and songs won't ever be translated by the Pioneer English dub teams or anything like that, sadly.
The best I can say is, once I get some more cash, I'll try to purchase the book itself via the Japanese auction site business. The problem there is that the partner has fees out the wazoo making it a very expensive endeavour. (Unless someone else wants to buy and scan it for us.

) I'm expecting a $60 item could be surcharged up to $100, give or take. That won't get you a translation, but at least then we'll have an online source for someone to work from if they should so choose to try.