transfer from one DW to another DW

Question

Hello friends.

I have a task as i'm migrating from 1 server to another i.e from NAV 2009 to 2013. in current DW i need to copy it to a new DW, and from there to cube.

where in the new DW contains old+new data.

later the old DW wont be in use.

please suggest me how to be done???

Thanks

Ranjan DS