I was able to take the stem part out of a valve stem, then replaced it with a piece of safety wire - and to make it extra pennytech, I used a used piece of safety wire!!
No pics, but I just used side cutters to cut both ends of the little stem off, the I used two pairs of pliers, one holding the body and one holding the bottom of the little stem - a quick yank and I had a hollow body. Then I just took a piece of safety wire and doubled one end over, then put the other end through the body - the doubled up end was big enough to lodge in the body. I suppose if one were spunky they could twist the wire and make it all pretty and stuff. Or, if one were not lazy they could post a picture for all adventure riders to see...