How do I get a replacement title? 

Replacement titles
Application

If your Wisconsin certificate of title has been lost, destroyed, or stolen, you may obtain a replacement by filing an application for title - registration form MV1 (150 KB) or MV5 (234 KB).
What is needed
The application must contain the vehicle identification number, the owner's name and address, and the signature of the registered owner. The vehicle identification number can be found on your registration card, or on the vehicle itself. Only the owner shown in Division of Motor Vehicles (DMV) records may apply for a replacement title.
Permission to pick up title is required
DMV now requires anyone picking up a replacement title for a vehicle they do not own, to present a completed "Permission to Pick Up Title" form MV2932 (79 KB), and show proof of identity in the form of a valid driver license or identification card. If the requestor does not have written permission or proper identification, WisDOT will mail the title to the vehicle owner.
A replacement title voids all previous titles.