instance document based on multiple schema

[AndiusMaximus]

Hi XML people,
I'm still finding my way through XML, I'm trying to build an instance document based on multiple schemas.

If have suite of schemas, based on the basic structure

Name.xsd (Firstname,Lastname)
Address.xsd (Street, Postcode)
Invoice.xsd (Total,Date)

If I wanted to build an instance document based on all three schemas, what do I put in the beginning of my XML document. How would it look structurally?

Thanks in advance

Thanks for you help.