How do i fix my overheatin citroen ax?

Having just purchased my second ax. I have come across a problem with it over heating. I am aware that in order to top up the rad you must bleed it. Where are the bleed points? And also maybe the thermostat has got stuck or blocked with sediments from the cooling system due to the car beeing stood for a medium length of time. If anyone knows how to locate the termostat your advice would be very handy.

Note K reg debut 950cc 89000 miles to begin with i had no problems with over heating it has just suddenly developed. also the heaters insider the car have stopped working in conjunction with the overheating problem!