This is not working. You need to unload classes from the object spaces where they were defined. Basically, i tried following:
```ruby
Crichton::Representor.send(:remove_const, :XHTMLSerializer)
```
then, unload representor:
```ruby
Crichton.send(:remove_const, :Representor)
```
and even unloading entire crichton:
```ruby
Object.send(:remove_const, :Crichton).
```
The thing is that if you do ```require 'crichton/representor'``` later it returns false, even though you cannot instantiate object anymore. This happens because ruby maintains $LOADED_FEATURES array, a global constant, tracking what is loaded and what is not. 

This will illustrate the point:
```ruby
1.9.3p327 :005 > Crichton::Representor.constants
 => [:Serializer, :XHTMLSerializer, :Serialization, :ClassMethods, :State] 
1.9.3p327 :006 > Crichton::Representor.send(:remove_const, :XHTMLSerializer)
 => Crichton::Representor::XHTMLSerializer 
1.9.3p327 :007 > Crichton::Representor.constants
 => [:Serializer, :Serialization, :ClassMethods, :State] 
1.9.3p327 :008 > Crichton::Representor::XHTMLSerializer.new
NameError: uninitialized constant Crichton::Representor::XHTMLSerializer
	from (irb):8
	from /Users/abrutski/.rvm/gems/ruby-1.9.3-p327@plinth/gems/railties-3.2.14/lib/rails/commands/console.rb:47:in `start'
	from /Users/abrutski/.rvm/gems/ruby-1.9.3-p327@plinth/gems/railties-3.2.14/lib/rails/commands/console.rb:8:in `start'
	from /Users/abrutski/.rvm/gems/ruby-1.9.3-p327@plinth/gems/railties-3.2.14/lib/rails/commands.rb:41:in `<top (required)>'
	from script/rails:6:in `require'
	from script/rails:6:in `<main>'
1.9.3p327 :009 > require 'crichton/representor/serializers/xhtml'
 => false 
1.9.3p327 :010 > $LOADED_FEATURES.select { |s| s.include?('representor/serializers') }
 => ["/Users/abrutski/.rvm/gems/ruby-1.9.3-p327@plinth/bundler/gems/crichton-e3932e4eef99/lib/crichton/representor/serializers/xhtml.rb"] 
```
One alternative is to use: load instead of require. It will always re-load the code, even if it is already loaded.