Look around the snooker room and go behind the grandfather clock to find the mouse hole on the floor. Click on a bobbin of thread in the hole to enter. A "Cheat Enabled" sign will appear. After leaving the hole, all players (including Jimmy White) will be accessible in the snooker and pool rosters.
Go to the pool room and click on "New Game". After that, click on "Demo/Trick Shot Editor". Next, click on "US 8-Ball". Place the cue ball anywhere on the table and remove all the balls except for the cue ball. Hit the cue ball anywhere, then click on "Replay". You should see the balls you removed on the screen. The cue ball will go straight through the balls, if you aimed at the space where the balls where located.