How Can a Foreigner Refinance His House ?

refinance

I bought a house in LA in 2001, after that I worked in USA for one year and bought more houses. Since 5 years I am visiting USA as a tourist and my Credit Score is 747.
Since 3 years I am working in Germany and pay Tax in USA only for my rental income from USA. Therefore my salary in Germany is not shown in my Income Tax.
How can I refinance my houses ?

thanks