Peter,
you need to be a subscriber to Drengin net. If you are then you can use the Stardock Central programme to download the beta. Go to the software area, click on the Drengin.net tab and it should allow you to update Galciv to Galciv 1.09A[b]. If not check your settings and make sure you have 'show pre-release alpha/beta' set.
If you don't have a drengin.net account then you could buy one or wait till September when the summer expansion will be released to everyone who bought Galciv.