So your employer needs to state what type of educational background or degree was required for you job, same with the work experience and skills see example below:
NAME was familiar with the SAGE accounting program, MicroSoft Office etc.. which was a key in hiring her/him. He/She had a degree in Business Administration which was a requirement for the position. Name 2 years work experience as an Office Assistant also contributed to the necessary skills and experience that was needed for the position that he or she currently works.
That's basically what they need, just make sure that all the information required are stated on the letter.