You will need:

This headless doll body from YMYDoll (or a headless Obitsu11 doll body from Parabox) Only use these 2 brands; this is important.

A tiny TV keychain, like this one from AliExpress (no link because the links change practically every week):

A 2mm screwdriver

An Xacto knife or other small blade

(Optional) A hand drill (I didn't use one)

Clothes to fit an Obitsu11 or similar doll

Start by cutting the keychain attachment off, unless you particularly like the idea of a dolly keychain for whatever reason. I don't judge.

Take the entire mechanism (carefully) out of the keychain. Make sure you remember where everything goes, so you can put it back in later. (You can remove the wires going to the tiny round speaker, if you don't want the "static" sound effect. I did.)

Cut or drill a 3mm hole in the bottom of the keychain, toward the back. (On mine, this is the blue part.)

Now for the tricky part. You see the white plastic piece that the LED shines into? You're gonna want to cut the bottom-right corner out of that piece so that the neck joint will fit. See image. (You can remove the back of this white piece, to take the LED out. I highly recommend doing that before you cut.)

This was really annoying to do, but my Xacto blade is dull. If you use a sharp blade like you're supposed to, it should take about 15 minutes. That plastic piece is thick, so go carefully and be patient.

One more step before we put the wires and stuff back into place! You see the extra neck joint that comes with the doll? The one that looks like this?

You want to use THAT neck piece. It has a screw in the top. Unscrew it, and carefully remove the pieces above the round ball.

Stick the peg into the head, then put the top pieces back on and screw the neck piece back together. This will secure the neck joint, so your doll's head doesn't fall off. You can also go ahead and install the neck peg into the doll at this point.

Carefully put all the electrical parts back into your keychain, being careful to put the white plastic piece back in around the neck peg. Your doll now looks like this:

If you want to draw a new screen for the doll, you can absolutely do that! I tried to draw static, but I'm not very good at it. If you're doing that, do it now.

Now, put the front part back on, making sure you didn't lose the tiny rubber button. Screw it in place.

And that's it! Dress up your new TV-head dolly however you want.