electric toothbrush in question .im sure this instructable would work for most toothbrushes with detachable heads you may have to adjust the tools needed i,e drill bit size.
Step 1: Tools You Will Need
hacksaw ,visegrips,drill,drillbits,file,tape, and of course toothbrush
Step 2: Cut the New Toothbrush Head Off
hackoff the new tooth brush head. length may vary depending on brand just leave enough too go over the shaft off said electric tooth brush
Step 3: File the End Flat
you may need to file the end flat and hasp off bures if you hav any remember this will end up in your mouth at some point
Step 4: Measure the Length of the Shaft
the length of your tooth brush shaft will vary depending on make and model. also drill bit diameter will vary. mark the drill bit with tape for depth doesnt have to go all the way to bottom.
Step 5: Start Drillin
be carful you might want to start a presunk hole and be sure and use visegrips and have a steady hand drill down first drill bit to the tape you marked on bit
Step 6: Now for the Second Drill Bit
i use a slightly larger in diameter drillbit and only go down 3/4 of the way i do this second drill bit step beacause at the tip of my brush head shaft is chamfered..
Step 7: Here It Is
brush head on the left cost 3.00$ and the one on the right cost 8.99$ at the oral-b web site