At the top right side of the desk set is a little lid that flips open where you should find the buttons to change the outgoing announcement and the number of rings before the answering machine starts, etc. A two digit "Remote Access Code" should be pasted to the bottom of the lid.
Phone the model 1810 and, after the beep, enter the Remote access code. After that, 7 will play all messages, 6 will play new messages, 2 will repeat messages, 5 will skip the message, 3 will delete the message.
john, October 2007