You would generate them the same as you would Invoices.  In Billing Manager, click on Print Invoices, Fill in the Client-Matter range and click on Print Actual or Draft.  Remove the check mark from Print Bills, and place a check mark in Print Reminders.

If you like, you may filter Reminders by selecting one of the following:

• Only for Matters Where Days Past Due is Greater than XX (number of days)
• Only for Matters Where Days Since Last Payment is Greater Than XX (number of days)
• Only for Matters That Have Not Been Invoiced Since the Date of MM/DD/YYY

SN: See the article titled “Printing Reminder Statements.”