# use mongoid
class User
  include Mongoid::Document
end


# then
user = User.where(email: 'joe@example.com').first

if user
  user.password = new_password
  user.password_confirmation = new_password
  user.save
end

# $ rails console production
u=User.where(:email => 'usermail@gmail.com').first
u.password='userpassword'
u.password_confirmation='userpassword'
u.save!

User.find_by(email: 'user_email_address').reset_password!('new_password','new_password')

u = User.find_by_email('user@example.com')
u.update_attribute(:password, '123123')

user = User.where(:email => email).first

user = User.find_by_email('user@example.com')

$ sudo bundle exec rails console production

irb(main):001:0> user = User.where("username = 'root'")
irb(main):002:0> u = user.first
irb(main):003:0> u.password="root2014@Robin"
=> "root2014@Robin"
irb(main):004:0> u.password_confirmation="root2014@Robin"
=> "root2014@Robin"
irb(main):005:0> u.save
=> true
irb(main):006:0> exit

user.locked_at = ''
user.failed_attempts = '0'
user.save!