You will need Desoldering braid, fine solder wire and flux, replacement battery panasonic lithium 3v three post stand part # br2330 you can find them on Allied Electronics

areas marked on the chip are to be Desoldered, they are the bottom of the battery posts Battery was already replaced in this photo
be sure to not over heat the board in the process to prevent any damage, I do not recommend working on a part that is under warranty, this was a second hand " junk " demon v1.2 chip with bent and broken dip pins and bad battery. After replacement of the battery and 28 pin dip socket the functionality should be the same as long as you have taken your time and was careful to not harm the boards tracks or other components.

 

I just got a deal on one of these.
This should be useful