Ok, now this might seem really hard for someone who has not done this before. Some good motivation could be needed. Reading the book "The China Study" by Colin T. Campbell would help of course - www.thechinastudy.com - it's about the connection between modern "western" degenerative diseases like heart disease, diabetes, osteoporosis etc and the foods we in the industrial nations consume in such large amounts. Definitely worth the effort, it has added much to my appreciation of the subject.

The plant-based-food-for-one-month challenge is spelled out in this book as well.
Enjoy the journey! you can always go back to eating steaks n burgers later :-)