轉自：http://blog.sina.com.cn/s/blog_76248ee40100ulvw.html
If you had the user's email address set properly (and the smtpconfiguration set properly), you could click login in the UI andselect forgot password, enter the username and email address, and anew password will be sent to you. If you do not have email setupproperly, you will need to manually edit the security.xml file,located in(nexus-basedir)/../sonatype-work/nexus/conf/security.xml. Firststop nexus, then open the file, and find the<user> object that has a<id> of admin. Then change the<password> tof865b53623b121fd34ee5426
c792e5c33af8c227 . This will give the adminuser a password of admin123 (the default) and you will again beable to login.
簡單地說，就是將密碼換成admin123的加密值即可。