1. Make sure you are running the latest version of Celebrant Assist 
2. Backup your data to a memory stick or similar device.
3. Download and install CelebrantAssistV3Setup on the second machine, as you did for your original computer.
4. When the program starts, follow the prompts to import the data from the backup.
5. Login.

Use the Backup and Restore functions to transfer the data from one machine to the other, as required.