How do I run the trial ends?

From Bowls SA's Markers Guide for Beginners:

• Ask the players whether they will play one or two trial ends. Either player may play one trial end of up to four bowls in each direction, even if the opponent doesn't want to.
• The players toss, and the winner decides who plays first.
• Centre the jack at the length the player on the mat asks for, not less than 23 m from the mat line and not less than 2 m from the front ditch.
• Don't stop any bowl, or put your foot on the jack, during trial ends. The player is entitled to see the full effect of each bowl, even if it moves the jack or runs into the ditch.
• Re-centre the jack if it is moved.
• Tell the player how far short of, or past, the jack each bowl finished.
• Remove each bowl by hand once it has stopped.