If you go to the Tequila options, it has an Installation Directory setting that you can change. After you change it and save the settings, close Tequila and move your game files to the new location you selected, then start Tequila again so it validates the files at the new location. Otherwise, it will try to download everything again, wasting bandwidth that we don't have a lot of (people with HTTP servers willing to be mirrors for COH files are always welcome; PM me).
Make sure you don't select a location that Windows has under its security blanket of UAC, like Program Files, or updates will fail. Try anything under your profile name (C:\Users\YourName\Coh) or under %LocalAppData% (C:\Users\YourName\AppData\Local\Coh)