so what happened to mosting your the model? if it's a DEI product all install/user manuals are available for download. there's a specific sequence you usally hafta do to get in/out of valet mode. usually something about turning the key then opening a door then pushing the button etc. unless it's a very very basic alarm it should have come with a valet switch. your installer should have told you where they put it. they also should have given you the USER MANUAL.

without the manual and knowing what you have it makes it a little hard to help you though.