How to replace a battery in a Casio fx-451M?

[Griff]

I have a Casio fs-451M (which is solar powered). This dates back to
the 1980s...

Anyhow, I recently rediscovered it in a long-lost draw and am pleased
to say that it works fine, except when the light is dim (the internal
battery is flat).

Can this battery be replaced?

If "yes", then what battery do I require and how do I replace it?

I created a support call with Casio, but they never got back to me...

Thanks if you can help

Griff

[eoin....@gmail.com]

Having just stumbled across an apparently dead fx-451m, I can tell you the battery is a GR927.

There are several plastic clips holding the left hand part of the calculator into the wallet part. The calculator then lifts out of the wallet, being attached only by the ribbon cable which links it to the right hand part. Four phillips screws hold the front panel on (be careful not to immediately turn it over once these screws have been removed as all the buttons fall out). After that, there are two more retaining screws on the other side which allow you access to the battery.