How to word an out of court settlement (details inside)

My co-worker was sued, and before the court date, made an agreement with the Plaintiff’s attorney to settle everything out of court for a sum of money.
This has been a verbal agreement so far, and my co worker wants to have a written agreement saying that the plaintiff will not pursue this case any longer.

Is there a standard form that he can fill out and have the other person sign that fulfills these objectives?
If not, what/how should he write it? can you point me to an example?

(His lawyer is unreachable, and he’s feeling uneasy)
Only serious answers please, seeking professional knowledge.

Much appreciated!