Fundy Album Builder and Workflow install the same way. Please follow these instructions regardless of program.
Double click on the trial package and open with your default archiving software.
Once you have extracted the folder, open it and find the Album Builder.zip file.
Repeating the steps above, unzip the Album Builder Trial.zip file in the directory of your choice.
Find the folder labeled "CS5 installer" and open it.
Double Click the .zxp extension to open Adobe Extensions Manager.
Click "Accept" and extensions manager will install the file into your extensions. If you had a previous version of Album Builder, It will prompt you to overwrite the file.
Open Photoshop, and navigate to Window>Extensions. Verify that Album Builder is installed.