setp 0:
install mvn. open settings.xml,append a line:
<pluginGroup>com.jayway.maven.plugins.android.generation2</pluginGroup>
setp 1:
enter project root dir.
setp 2:
mvn eclipse:clean eclipse:eclipse -U -e -Dandroid.sdk.path=/Users/cqtouch/Downloads/adt-bundle-mac-x86_64-20140321/sdk
sdk.path is yourself path