Tilting the Fob to the side, there is an opening.

And yup, you guessed it, the mighty Spuger pops this open!

Once open, we can see that there is heaps of room for a flip key. Toyota again, why did you bother designing a seperate Fob again?

Notice the rubber pad, this is for the buttons, I found the original pad to work better in the new key. Totally up to yourself if you mix and match parts.

Carefully remove the PCB from the shell, save this as we will use this later for our new key.

Ensure Battery has been removed in previous step, as it can cause damage to the PCB. Also, avoid using a metal tool here incase.