Among the many possible cases :

Make a backup of the current logbook with the option Tools → Backup/Restore. Make a backup on a removable media.

Connect the removable media to the new computer and restore it with the option Tools → Backup/Restore.

The last versions had a Copy function. General menu option Tools→Export→Copy logbook. Choose in the file explorer or finder a folder located on a removable media.

Then follow the restore process described in the last paragraph.

You only have the computer disk or a backup of this disk. Whatever the Logfly version, by default Logfly installs the logbook in a Logfly subfolder of the Documents folder (Mac) or the My Documents folder (Windows). This default logbook is named logfly.db. If you have created another logbook, the extension is always .db. You have to copy all .db file(s) to a removable media.

If you had chosen another folder, you will have to search for files with the extension .db.

Install Logfly 5. A Logfly folder is created in My Documents (Windows) or Documents (Mac). The default folder is logfly.db.

Open the settings window. On first tab called Logbook, click on the Repatriate a copy button and choose the removable media. The logbook is copied to the default folder. This logbook becomes the active logbook. Repeat the operation if you have several logbooks and select the logbook to be activated in the drop-down list.

When making this change, our advice is to use one of the many free cloud services. This allows you to have a permanent backup, using Logfly on several computers with different operating systems. See the cloud installation page.

If the default folder [My Documents (Windows) or Documents (Mac)] does not suit you, copy the logbook(s) to a folder of your choice. Launch Logfly and open the settings window. On first tab called Logbook, click on the Choose a new logbook folder button. Select the chosen folder and confirm. Logfly will search for all .db files in this folder. Select the logbook from the drop-down list.