Remove features without lose functionality
You can use the Features Tools Module to disable a features module while leaving the functionality that was provided by the feature in place.

Instructions provided by autopoietic here.


  
  First BACKUP YOUR DATABASE
  backup your feature (files) if you would like to use it again.
  Once installed, go to the 'recreate' page for a feature, uncheck all of the features
  components
  In order to save the elements to the DB you need to go to the admin/build/features/unlink
  page, check the element you need to import and submit.
  Now click on the 'Safe autocreate' button to recreate and replace the feature with an empty
  version.
  You can now disable the module without affecting your site configfuration.
  


These instructions note that "if you are using D6 there is an extra step" which I have added (step 4 above).