change joomla orientation of things

[rebeka]

I wanted to figure out how to do some visual changes in joomla 1.5for example I want to change the place of menu in admin menus, or some changes in buttons that are in different parts of admin menu(somewhere like add/remove components).or in the pages like adding and removing components, I want to do some changes in the tables that show data, for example I want to delete a column or do some changes in column contents.and I don't wanna make these changes in an specific theme or sth;I want that my changes affect all themes.thanks