4063 claiming residency in Italy.

Hi,
I am new to the forum, I have searched through and seen the discussions on residency in Italy, but still have some queries.
I bought a house nr. Montepulciano last august, in just my name and under seperazione di beni , and need to claim italian residency when I go in September this year in order to escape paying the rest of the tax.

1. I dont know yet whether I will be spending 6 months of the year in Italy - is this the legal requirement in order to get residency?

2. How do I actually claim residency, I have a codice fiscale and all the documents from the purchase of the house, what other documents do I need and where do I go to do it?

Any help would be very gratefully received.
thanks
sarah b