You have to hold and drag an app (then drop on top of another). When you release, a folder will be created, which you can give a name.
Settings -> Mobile Hotspot and Tethering
Fourth option from the top, in the Wireless and networks section
Pull down from the top (notification panel) > pull down again right below the search box (double line icon) > drag the Mobile Hotspot icon (toggle switch) where you would like it to be. That is the easiest way my friend has found to toggle it on/off.