Disassembling a laptop is a big pain, especially if you don't really know what you're doing. It is possible, and easier if you actually have a manual or a tech manual which gives you step by step instructions for each part you want to replace (like Dell provides for DCSE certification).
You may actually only need to remove the palmrest assembly to get at the fan though. This may or may not require removing the LCD panel. Even if you don't replace it, oiling the bearing may help a lot, if it's functioning at all.
But no, that laptop isn't really worth much except to someone who has no other way to have a computer. If you can find a place to donate, that'd be nice, or ebay it yourself.