Best Practices

When we originally began using the Asset module, we manually created an asset field, called Status where we could select either Active or Surplus.  Now in version 8, we see there is a newly created asset field with a drop down menu for Asset Status, with selections like Active, Disposed, Expired, etc.  In the past we would use a spreadsheet saved to CSV format and update our manually created Status section.  Would the same work for the newly created Asset Status field with the drop down menu?  I'd like to start using that new Asset Status, but I have 500 computers that are marked Active with our manually created Status field.  If I delete our manually created asset field those 500 machines will lose their Active status.  Is there a way to update those 500 computers under the new Asset Status field without having to manually update each one individually?  Any advice would help, thanks!