See here how to reset part of your Nex data or the entire database.
1. On your computer desktop, click on the upward-pointing arrow symbol, in the lower right corner, and then double-click on the NEX SERVER icon.
2. Click on the RESET menu.
3. Select the information you want to CLEAR and click on DELETE DATABASE INFORMATION.
4. Press YES to confirm.
5. Press YES again to confirm the operation and carry out the procedure.
6. Wait for the process to complete and click on OK.
Done! Now just access your Nex and start filling it with the data you want!