'View','Toolbars','Customize'
Choose toolbar to change from 'Select Container' dropdown (top left)
for small choose 'Menu Icons' in drop down bottom right or for big choose 'Toolbar' icons
It's a bit buggy so if your selection won't stick, drag the toolbar off of The bat!, try again and drag it back on.
Also if your positioning won't stick, postion them one at a time and shutdown when positioned using 'Message', 'Exit'. Rinse & repeat, That will eventually work. Once it works you can close however you want.