I'm not familiar with a Clio but the principle of bleeding on engines and cooling systems will be the same.
You will have two rubber hoses about an inch or so apart, these rubber hoses come out of the bulk head, then connect to the the engine, both of these hoses should be hot when touched, although one will be slightly hotter than the other.
Where the hoses come out of the bulkhead, one of them will have a bleed nipple this usually is a plastic thumb / finger screw. Have a good look around the cooling system checking for more of the same sometime there are 2 sometimes 3 when you're convinced you've found them all
Warm the engine for about 5 mins
To avoid being scalded Very Carefully and slowly,
remove the filler on the plastic header / over flow tank, fill the tank up with a mixture of 1/3 antifreeze and 2/3 water.
Starting from the lowest bleed nipple in the system open it a couple of turns you might hear the hissing of air coming out of the system let it continue until your get nothing but a steady stream of water, when this is so, close the bleed nipple. Then continue in the same manner with the next highest bleed nipple. All the time keep your eye on the coolant in the header tank / overflow bottle don't allow the coolant level to disappear below the bottom of the bottle.
Also try to judge the coolant level to be at the max level marked on the side of the bottle at the closure of the final bleed nipple.
Finally after letting the engine go stone cold check and top up the coolant level again if required.
It's a bit like that.