Drill a 2.5mm hole in the thermostat flange (if you have not done this already) as, without a jiggle valve, the near side pipe from the rad cannot bleed the air because the bleed nipple on the stat housing is above the stat.
As Si says, get the rear of the car as high as practicable so the air can travel towards the engine from the horizontal pipes under the car.
When bleeding the rad, remove completely the bung so as there is a good flow of coolant... if you just let it trickle out, the coolant can bypass air pockets without driving them out.
Between bleeds, fill slowly to allow air to pass through the stat hole, and also be able to back up to the reservoir.
Bleed cold.
Having done the above, run engine... let cool, check and top up level as necessary. you should only have to do this once. as the running engin will expel any air pockets up to the reservoir.
