First of all, here is the main ONLINE SUPPORT page for your model:
And here is a direct link to the ONLINE USER'S MANUAL for that model:
To view the Support Page or the Owner's Manual with Operating Instructions just use your mouse to click on the link, which is the underlined and highlighted text just above. This will open a new web browser page automatically for you and allow you to view the information at the website indicated and the contents of the Owner's Manual.
You may need ADOBE READER installed on your computer to read PDF documents.
You can download this free at WWW.ADOBE.COM
Click on the DOWNLOAD ADOBE READER button on right side of the ADOBE home page when you get there, then follow the onscreen instructions to install the software on your computer.
See page 27 of the manual for detailed instructions on how to use the TV and exactly how to switch input sources.
Basically you just connect your DVD player cables to the appropriate input connectors on the back of the TV. Also make sure your DVD player is fully powered up and turned on. See page 23 of the manual for detailed diagrams of the correct cable connection procedure for your device.
Then push the INPUT button on the TV or on the TV's remote control repeatedly until you get to the correct INPUT MODE, then press OK to confirm.
Please comment back here to this page if you have any details to add, have any questions, have difficulty accessing the links, or just require further general assistance and I will respond as soon as I see it.
I hope that was helpful to you, good luck and take care.