How do I arrange or reorder slots?

You can drag and drop slots to any other position by clicking on the slot number at the left.
Rearrange slots
After dropping a slot somewhere a dialogue appears:
Hotkey reordering#
It asks you whether you want to move the Hot key along with the slot. If you are not familiar with the principle of hot keys and/or do not care which hot key this dedicated slot has, simply click "No" (and go on reading here). After finishing the action like this the slot has a new place, a new slot number and a new hot key. Well done, boy!