You'll need your tripod of course...
Take that plate off the head. You won't need it
Hold your device to make sure it will lay flat.
Take a rubber band, hair tie, or hand band. (anything stretchy) and put it around the release handle.
If your handle doesn't stick out, just put it around the head like this ^^
Loop around your device and the tripod.
Make sure the part that you are holding is going under the handle.
Now put it around your device's other side. Make sure that the tension on both sides are equal.
And there you go! If your tripod is nothing like mine, put you device on a flat part of your tripod and get a whole bunch of hair ties and rubber bands:)