how do i draft a cover letter for this

A client, Sarah Smith, at the law firm where you work as a paralegal would like to enter into an agreement with Evonne Young.Sarah would like to sell to Evonne a one-carat square diamond ring that Sarah no longer wears.The diamond does have a slight flaw in it, which Sarah has pointed out to Evonne.But Sarah wants to make sure the agreement reflects the flaw, so there is no chance Evonne will ask for her money back due to the flaw.Sarah and Evonne have settled on a price of $800 for the ring.They want to close the deal on a date on August 8, 2018.

The senior attorney in the law office, Marianna Rodriguez, has asked you to draft the contract for her review.