This is what I believe I need to do:
2 x people required no speed bleeders at present.
For the last part, yes. You can gravity bleed the system for a while... clean and flush all of the old fluid from the reservior (using a brake fluid tool works great... it is a little like a small turkey baster with a very thin snout). Then open the bleeders and let them drip in som catch cans for a while, topping off the reservior as needed. When the color of the fluid coming out of each caliper is good, you can shut it off in prep for the next stage.
One sit in car with windows open while the other completes the task of opening the bleed nipples.
Person Two does the following:
Go to each calliper
release the bleed nipple, shout out to driver to press pedal as he/she does, this forces the brake fluid through bleed nipple to allow fluid out in to catchment container
The person in the car should push slowly, and never go more than half way. The reason is that the master cylinder can develop pits at the far end and may damage the seal.
Once initial fluid is out tighten nipple then tell driver to release pedal, then repeat process until new fluid comes through then tighten bleed nipple (not overly just enough to seal) move on to next calliper.
Just do this 3-4 times per caliper once you're done with the gravity bleed.
If air has got into the system at any point (replaced compenents, whatever), or you just want to be a little paranoid (no harm), then do the following:
Call out "pressure" to the person in the car. This is their signal to pump up the brake pedal until it gets firm, again being careful to not stab at the pedal and not go more than half way per stroke. Once they have a firm pedal they hold pressure on it. The person at the caliper can tell that this is done, although you can work out some kind of safety word for this part. In any case open the bleeder very slightly. Once you see no bubbles for a couple of tries, you're done.
Whilst carrying out this process keep an eye on Brake Reservoir level and making sure it doesn’t empty, top up when it gets low.
Yes, this is very important. Once air gets into the system from the reservior it can be a bit tougher to get out.
When you're done the person in the car should be able to pump the pedal and get a good solid feel to it. If not then try starting the car and seeing if it feels good with the booster working.
That should do it.
BTW, I have some speedbleeders on my shelf that I never use, because the above procedure works very well.