I highly recommend you spend these days doing a pre-cleanse diet. Eat ONLY fruits in the am, veggies in the pm... cut out coffee, sugar, breads etc. Just the fruits and veggies, and all the fresh juices you like.
Then you will definitely have an easier first week!
Juice fasting will do all you mention and MORE! I cannot tell you what wonders it has brought into my life over the past three years!