After an initial  to schedule the work, simply or your instructions for the project.

Include any notes or drafts that you've already created, and anything else that will help me understand your requirements.

If format is important, send me a sample of what the document should look like.

Explain your review process.  Tell me your deadline and provide your contact information in case I have questions.

Then, leave the rest to me!  I'll fix your document and return it by the date you specify.