Replacing Battery in 7100

I have an old PowerMac 7100 which I bought refurbished about 5 years ago.

About a week ago, the clock stopped keeping time, and other settings are disappearing on restart.

1. Is the battery readily accessible? Are there any tutorials online?

2. What is a good source for new compatible batteries?

The battery is cake to replace. Just open up the computer and look for it. it looks like a 1/2 AA battery.

Try here: http://eshop.macsales.com/Catalog_It...Item=OWCMAC36V

Thanks - since I'm all thumbs when it comes to things like this, now I know I won't have to poke around excessively and break something. :)