First of all, the printer you want to print the document on needs to support AirPrint.
1. Open the document in PDF Viewer and tap on the "Activity"-Button.
2. If you want to include annotations in the printed PDF, then please select "Embed Annotations", if not then select "Ignore Annotations". Then tap "Share".
3. Tap on the "Print"-Activity.
4. Select your printer and tap on "Print".