The german Espace repair manual from Bucheli Verlag is somewhat depressing in their recommedation (my translation):
The removal and replacement of the radiator is a big job, since the entire front of the car must be removed before the mountings of the radiator can be accessed. And on vehicles with air conditioning, the system must be opened and refilled, which requires special equipment [blah blah they really don't care to describe the procedure afterall].
On the other hand, the french manual from ETAI gives a specific procedure about how to refill the air conditioning.
Anyway, it seems that the radiator is taken out from underneath the car! Not from above...
Oops!. It seems like a hard job... it is a pity, as I have replaced several radiators in other cars, including my CitroÃ«n XM 2.0 TCT, which has also intercooler and aircon (so there are three radiators side by side!), and I did not need to remove front nor regas aircon
I have been checking regularly coolant level and it seems to stabilize at about minimum level... My wild guess is that with more coolant, pressure is higher and coolant get lost by the joint between plastic and metal radiator parts but with less pressure it does not happen... just a guess but it seems to be doing just that.
So, if coolant keeps at that level, I think will left it as is for some time. Of course, I will regularly check it!
Thanks and best regards,