How do I change message on answering machine? Misplaced my manual.

SOURCE: how do I set up my answering machine with a new voice message?

Press and hold the record new greeting button on the base station

SOURCE: I have misplaced my manual

You can download the manual from the manufacturer's web site at
http://uniden.com/pdf/EXAI5580om.pdf

SOURCE: cannot replace outgoing message on

Since you didn't say what model you have, select it from the list beginning at
http://www.uniden.com/bin/venda?ex=co_disp-view&bsref=uniden&scat=dectphones_mnl