I have got the WiFi-Only Motorola Xoom tablet and bought a Verizon 3G SIM card. I find a guide for getting 3G Xoom to work on another carrier, so can I activate 3G on my WiFi-Only Xoom? How to add the Verizon 3G SIM card to activate?
You can't activate 3G mobile data on the WiFi Only Xoom. It's impossible. The hardware are different between the 3G version and the WiFi version. The WiFi only version Xoom doesn't have the hardware required to connect to any carrier networks.