Hi @josephrdefr1958
Here's a [https://www.youtube.com/watch?v=hkFZKKrboaI|video] that may help.
I realize that it is not the same model remote but usually they're opened in the same way.
I suggest that you get an [product|IF145-335] rather than using the screwdriver as shown in the video as this will minimize any cosmetic damage to the case of the remote whilst it is being opened.