Installation

Step 1: Download the lightning plugin then the synckolab extension (use "rightclick/save as" otherwise firefox will try to install it)
Step 2: Open Thunderbird and use Tools/Extensions then install the downloaded calendar and the synckolab xpi
Step 3: Restart Thunderbird
Step 4: Configure the plugin

(1) will open the configuration wizard

Optional:

Step 5: get the icon

rightclick on the icon bar (2) (next to Stop) go to customize and drag the "Sync Kolab" Icon (3) to the bar (4)
Step 6: click the icon or menu entry and the sync will start
Optional: Since you cant drag the button into lightning, try the Custom Toolbar extension and create a new toolbar there.
MAKE SURE YOU READ THE RELEASE NOTES OF THE VERSION!!!