1.删除先前版本的elasticsearch

sudo apt-get --purge autoremove elasticsearch

2.删除elasticsearch目录

sudo rm -rf /var/lib/elasticsearch/
sudo rm -rf /etc/elasticsearch

3.安装elasticsearch 1.6

sudo dpkg -i elasticsearch-1.6.0.deb

4.启动服务

sudo service elasticsearch start

5.测试是否有效

sudo service elasticsearch status
curl -XGET "http://localhost:9200/_cluster/health?pretty=true"
curl "localhost:9200/_nodes/settings?pretty=true"

参考文献：
Ubuntu卸载elasticsearch