Simplify the following text for a Grade 9 native English-speaking person.
Original: He followed this up with a further two goals against former employers Hibernian at Easter Road on 28 September 2008 , then adding his sixth goal back in a Rangers shirt at Rugby Park in a 4-0 win over Kilmarnock .
Simplified: He followed this up with a further two goals against former employers Hibernian at Easter Road a month later .