Download the STL file and upload it to Shapeways. Select 'Elasto Plastic' as your material and fill in your own address.
Scrape the inside of the printed part to remove all the white dust. Then wash it with water to make sure all is gone. If you don't do this, it will not fit.
Remove the regular TOH from your phone (this is a bumperTOH, not a bumperCASING), and insert your phone top-side first. Push it all the way in.
When the upper part is up to your satisfaction start wiggling in the bottom part. Be very carefull, because the material will tear if you rush things. Use a small stick on the inside (at the speakers) to get the material pushed into the right place.
Lastly massage the casing around to get it into the right place. This casing is not meant to be taken on and off all the time.
That sucks. Order another one, but read through these instructions first the next time.
That is extremely unneccessary, but very friendly! It is also very encouraging for me to keep developing and you can use it to give an extra push to your idea or suggestion. Not like a bribe, but I can allocate more time to it.