XPS-9550 swollen battery. How do I replace?

I have the Dell XPS 9550 15" and my battery is swollen and need to be replaced ASAP - but I cant seem to find the part on Dell.com? what should I do?

• I suppose I need to know the exact part # or model number of the current battery. How do I find this out with opening up my laptop?
• Do I need to know any other specs. in order to order the right replacement part?
• And can a non-tech easily replace the battery on my laptop,or is this over my head?
• Will I need special tools to do this??

Thanks in advance - Ashe