Is it Easier/ more successful to change 1 hose and bleed then the next then bleed and so on?

Also if I want to replace the fluid can I just keep topping up the Eezibleed system without having to drain all the brake fluid 1st and just push the old stuff out ?

How much fluid does the system take ?

Cheers

No change all the hoses then bleed. Keep the reservoir topped up if you can, so yu don't get air locks. Make sure the lid is kept on to restrict fluid loss, when changing hoses.