The question is in the title : How to remove buttons from CKeditor 4 .
Documentation does not answer it clearly
To remove buttons, try:
$(document).ready(function() {
CKEDITOR.config.removePlugins = 'Save,Print,Preview,Find,About,Maximize,ShowBlocks';
});
The comma-separated list must contain the name of each button you want to remove. The following link is the complete list of the buttons containing the toolbar ckeditor:
list-buttons