Whichever way you write it, I'm sure he'll get it. No need to put "No." after the street name though, and I believe that the apartment no. is 3D-E, therefore I would put it after "Edif. Orosol", and then "Spain" should go on a line last

Spain Malaga Mission
Av. Jesus Santos Rein 2
Edif. Ofisol 3 D-E
Fuengirola 29640, Malaga
Spain

The area is crowded with tourists, but if he goes a bit inland it's a different scene. Also, tell him that further south along the coast is beautiful - I quite like Estepona.