Press "Start", which has an icon of a home button. Then press the "menu" button, which has an icon from the list. Tap "Settings" on the touch screen, then tap "Applications".
Select "Manage Applications" and then wait for the list to appear. It will take a few minutes, while the Nexus One scans the installed applications. When all applications have icons loaded, you can move on. Choose the application you want to move to SD card.
Press the "Move to SD card" button. Wait until the application is copied to the SD card. When the process is complete, the button text will change to "Move to phone". Repeat this process for all applications to be moved to the SD card.