dead battery

Hello,
I have a Hp pavilion and the battery - a lithium-ion (hp f809a/f4812a has never held its charge properly. HP refuse to repair it since I now live outside the US. The battery holds no charge, but indicates 100% on the battery dial. The battery test does not work from the computer.
The battery will not turn the computer on at all.
Since I cannot have it repaired under guarantee, I want to mend it myself.
Is there a website / any information on repairing laptop batteries? as I do not have enough money for a new battery cos I am not working anymore.
Thanks for any help/advice
Chris

 

Thanks for the reply, unfortunately the site doesnt have any specific info e.g step by step guide.
HP only mail to the US and I am in the UK, that has been the problem about the replacement (cost 130 pounds here new)

Is there any driver/override software which can glean any info from the battery via the computer as to what is wrong or where the problem lies?
I have tried batterymon but it just says the battery is full.
thanks
chris