Complex sentence: Around that time, the staff at the Blood Bank's Mandarin Center convinced him to try Apheresis, he discovered that that the procedure was tolerable, so he switched to apheresis every eight weeks.
Split into simpler sentences: Around that time, the staff at the blood bank's Mandarin center convinced him to try apheresis. Greason found that the procedure was tolerable, so he switched to apheresis every eight weeks.