Reset jenkins password

0. SSH to server
1. Edit /opt/bitnami/apps/jenkins/jenkins_home/config.xml

2. set userSecurity to false: <userSecurity>false</userSecurity>

3. delete
<authorizationStrategy> and <securityRealm>

4. /etc/init.d/bitnami restart

Now Jenkins should be open:

5. Select Configure Jenkins,
    "Enable Security", 
      "Use Jenkin's own database"
      "Allow users to sign up"

6. Under Authorization, select:  "Matrix-based security"
   and add users and give them all permissions, 
and remove all permissions from 'anonymous'

//------------- To Reset individual password:
    Go to /opt/bitnami/apps/jenkins/jenkins_home/users/gmhawash
    Edit config.xml file
    Remove the passwordHash tag (you can now log in without password)

//------ refer: https://gist.github.com/gmhawash/4043232