```ruby
Spree::Address.class_eval do
  belongs_to :user

  attr_accessible :user_id, :deleted_at

  def self.required_fields
    validator = Spree::Address.validators.find{|v| v.kind_of?(ActiveModel::Validations::PresenceValidator)}
    validator ? validator.attributes : []
  end

  # can modify an address if it's not been used in an order
  def editable?
    new_record? || (shipments.empty? && (Spree::Order.where("bill_address_id = ?", self.id).count + Spree::Order.where("bill_address_id = ?", self.id).count <= 1) && Spree::Order.complete.where("bill_address_id = ? OR ship_address_id = ?", self.id, self.id).count == 0)
  end

  def can_be_deleted?
    shipments.empty? && Spree::Order.where("bill_address_id = ? OR ship_address_id = ?", self.id, self.id).count == 0
  end

  def to_s
    "#{firstname} #{lastname}: #{full_address}, #{city}, #{state || state_name}, #{country}, #{zipcode}"
  end

  def full_address
    [address1, address2].reject(&:blank?).to_a.join(', ')
  end

  def destroy_with_saving_used
    if can_be_deleted?
      destroy_without_saving_used
    else
      update_attribute(:deleted_at, Time.now)
    end
  end
  alias_method_chain :destroy, :saving_used

end
```

Remove user association from address instead of setting deleted at flag
user
```ruby
Spree::Address.class_eval do
  belongs_to :user

  attr_accessible :user_id, :deleted_at

  def self.required_fields
    validator = Spree::Address.validators.find{|v| v.kind_of?(ActiveModel::Validations::PresenceValidator)}
    validator ? validator.attributes : []
  end

  # can modify an address if it's not been used in an order
  def editable?
    new_record? || (shipments.empty? && (Spree::Order.where("bill_address_id = ?", self.id).count + Spree::Order.where("bill_address_id = ?", self.id).count <= 1) && Spree::Order.complete.where("bill_address_id = ? OR ship_address_id = ?", self.id, self.id).count == 0)
  end

  def can_be_deleted?
    shipments.empty? && Spree::Order.where("bill_address_id = ? OR ship_address_id = ?", self.id, self.id).count == 0
  end

  def to_s
    "#{firstname} #{lastname}: #{full_address}, #{city}, #{state || state_name}, #{country}, #{zipcode}"
  end

  def full_address
    [address1, address2].reject(&:blank?).to_a.join(', ')
  end

  def destroy_with_saving_used
    if can_be_deleted?
      destroy_without_saving_used
    else
      update_attribute(:user_id, nil)
    end
  end
  alias_method_chain :destroy, :saving_used

end
```
assistant