How to Un-Install Category Module?

When my website was originally started the developer installed the category module, but from what I remember it was not used after a few weeks. I later took over developement and when the site was upgraded to 5.0 the Category module was not installed. The site has been running fine for almost a year now

In an attempt to tidy up before moving to drupal 6.0 is it safe to just delete the following tables from the database that relate to the category module? Is there anything else that needs to be adjusted

category
category_cont
category_cont_distant
category_cont_node_types
category_display
category_export
category_hierarchy
category_legacy
category_legacy_map
category_menu
category_menu_map
category_node
category_relation
category_synonym

TIA for any help you can give