Brake fluid quantity

Does anyone know how much brake fluid is required to fill MY02 b4 legacy.
I'm upgrading from dot 4 to dot 5.1 and need to know how much to order.
Also any tips? I was just gonna take off all callipers and turn them upside down and wait for fluid to drain from pipes.
Cheers,
David

Not sure about the procedure but it will take about 7-800mls to fill the whole system. Get yourself a litre and that'll do you and cover any possible spillages.

Cheers robbie