Old way is to get an assistant to squeeze the brake pedal while you open the bleed nipples. As the pedal sinks you close the nipple and repeat. Need a tube and jar to collect the old fluid. Keep topping up the reservoir with new fluid and keep bleeding until the colour coming out changes from dark to light. Start with the brake furthest away from the master cylinder and work across and forward. Don't let the master level get too low as air can be drawn in and don't let the pedal pusher push it too far and risk reversing the seals. Pressure bottles are available from Sealy and Gunson ( £20) which use tyre pressure and make it a much simpler one man job with no pedal pushing and no repeated opening and closing of the nipples.