I too would be interested in this. The requirement to have Docker and VMs shut down to even consider touching networks in the GUI is inane, and turns what should be 5 seconds into a 10+ minute reboot process.
Hypothetically, something like
ifconfig br0 down && ifconfig br0 up
should do. Maybe would need to use your eth0/etc itself depending on what's actually getting hung up.
But in my experience, that has done nothing for the problem I've had at hand despite all indications that it should work.
So your mileage may vary.