Complex sentence: The construction of the stadium was kicked off in 1980 based on the design of the Polish Constructor with the assistance of architect "Fawzi Khalifeh" and it was supposed to be completed in 1987 to become ready for the Mediterranean games.
Split into simpler sentences: The construction of the stadium was launched in 1980, based on the design of the Polish constructor/architect, with the assistance of architect "Fawzi Khalifeh". It was scheduled to be completed in 1987 to become ready for the Mediterranean games.