1.新建一个新的用户user2
sudo adduser temporarysudo adduser temporary sudo2.从user1 logout。进入新建用户user2，修改user1的名字和home目录名
sudo usermod -l new_username -d /home/new_username -m user1
3.从user2中logout，进入user1(new_username)，删除user2.
sudo deluser temporary sudo rm -r /home/temporary
usermod -l new_username -d /home/new_username -m old_username
permissions - How do I change my username? - Ask Ubuntu
原文：http://www.cnblogs.com/jiangz/p/7576861.html