Correct Writ Add Post-Judgment Costs

1. I want a demand letter for money owed 2. I want to update a writ i have against my ex, for this debt, to include post judegement interest and the costs of this freelance project 3. I also want to know... (Budget: $250 - $750 CAD, Jobs: Editing, Legal Consultation, Legal Research, Legal Writing, Proofreading, Research Writing, Word, Word Processing)