That are two ways that you can do that (off the top of my head). The first way is to simply resize the partition, which could be easily done with a live CD (eg: Ubuntu) and gparted. The other way could be done by using a file as a swap file. Take a look here:
with live cds you have to be careful because when using a livcd on a linux system it will try to use the available swap partition then mount it.
you will be unable to unmounted a swap partition. You must use the option to run in ram only mode. like puppy linux boot command puppy pfix=ram
or any of the F1,2,3 options on the live cd.