Sonicare Healthywhite HX8911 Tighten Head

you will need a thin, flat screwdriver to go in and pull all four sides a little at a time up by levering the rubber seal and plastic out. This model does not use those clips in the green head image, but just a push in black rubber seal you see the second image. Be careful to not wedge too much on any one side too far, go around on four sides a little at a time so you don't bend and warp the white plastic body.

Supplies

very thin flat screwdriver, try a few different ones. nothing round like a tiny phillips head. Maybe a long thin pair of needle nose pliers, two toothpicks possibly, and a phillips head that is small enough to rotate the screw at the end.

Step 1: Inner Clips Need Two Tiny Flat Screwdrivers or Picks to Lever in and Push the Body

The guts are held in by two angling plastic clip heads you can see in the first two images. They barely clip into the body iself as you can see the white housing alone. You can put two tiny screwdrivers or anything that will push the heads in a bit towards the center. The black tabs go in, and it gives space to push it all out with the metal head on the other side into the body.

It is possible to maybe use a strong toothpick on each side, but awkward as you need to tilt out opposite directions to get both of those plastic tabs to go in. Maybe a very long pair of needle nose pliers will work with tiny heads and long tongs.

Step 2: The Clips and the Battery Cover | Lights

The clips are very clear now and it is easy to see how to fulcrum them in to push the unit out of the white case. The battery cover just pushes on, not very well at all. The electronics, wires and SMCs are delicate be careful when you fix this unit and push it back in.

Step 3: Flattening the Head But Not Too Much It Has an Angle

Notice that the head is loose in the first image and you can feel the play in it. The phillips head screw can be tightened as you press it into place, you will mechanically play with this until you feel it is right. Remember there is the slightest design angle when it is in place.

Don't tighten it too much where it is super tight.

Step 4: Tightened Head and the Angle

You can see even properly tightened that the head has a bit of an angle by design. Don't try to bend anything, your toothbrush system probably will never be able to bend/break. Just pay attention to the mechanical design and you're set to push it back in and fix the seal.

Step 5: Push the Unit Back in the Case

Push the unit back in the case and you will be set. The clips naturally go in without any fuss, and then the green plastic cap goes on with no tools. Notice in this model you might think those green clips go somewhere but again they don't.

Look closely in the first step, you will see the writing on the bottom, and or notice it is taller, or rectangular. Don't put this in 90° degrees the wrong way. Look at the plastic body and the cap. It can obvious go in 0° or 180

°. It works either way. Turn it on, and test it out, then with a brush head properly put on top as usual.