A video, to show you how to do it?
A video might show connections happening at one point, but you couldn't see how wires go to grid and existing inverters.
The drawing posted above shows PV inverters connected to AC1 of Sunny Island, and grid connected to AC2.
Look up another drawing showing PV inverters connected to grid.
Cut wires between PV inverters and grid, insert Sunny Island, connect the wire ends to AC1 and AC2 as shown.
Finer points:
1) Determine if your existing GT PV inverters implement frequency-watts (a feature of UL-1741-SA or Rule-21, might require firmware update.)
2) In the U.S., Sunny Island is 120V but most GT PV inverters are 240V, so two Sunny Island are required
3) Limits on how much GT PV wattage can pass through to grid, and how much can be managed while grid is down. Review specs and manual of whatever battery inverter you plan to use.
There are other ways to make the connection, depending on your existing system configuration, how automatic you want this to be. I could just connect a pair of Sunny Island to existing breaker panel (AC2 input to one breaker, AC1 to a second breaker with interlock to main breaker) and use that for manual switchover.
Unless inverters and battery are large enough to power entire house, you will need to either manually disable excessive loads or wire the system to only back up smaller loads.
In case you get that wrong, it is useful to have a way to automatically shed most/all loads and keep only critical loads or just GT PV powered so batteries can recharge.
Grid Tie PV is trivial to design and implement, and almost any system just works. Battery Backup requires design and decisions.
A video isn't likely to document everything. Schematics and user manuals do, and posting your design for review would give an opportunity for problems to be caught.