Complex sentence: Having graduated from Okrika Grammar School--nicknamed Old Garri sellers during his time--in 1986/1987, he went further to University of Science and Technology, Port Harcourt where he studied Medical Laboratory Sciences, specializing in Haematology and Blood Transfusion.
Split into simpler sentences: Having graduated from Okrika Grammar School in 1986/87, nicknamed Old Garri sellers during his time. He went further to University of Science and Technology, Port Harcourt where he studied Medical Laboratory Sciences, specializing in Haematology and Blood Transfusion.