I am willing to do this again for version 1.5 but I do not want to risk losing all of my work that I have done to my widgets and what not.
Try the following steps,
– Activate any other theme like Twenty Thirteen temporarily.
– Delete Contango old version
– Upload Contango new version and activate it.
– Settings will not be disturbed.
If you feel easy to use FTP client. Simply overwrite contango old folder with the new one.