You can use Gparted to edit partitions. Delete the unwanted swap partitions and add a new one. Try to avoid moving existing partitions, as this operation takes a long time, although in-place resizing is usually pretty fast. Basically, if the tan part moves, it'll take a while. And back up everything important first.

Swap partitions tend to be recognized automatically, but you can edit /etc/fstab to tell it to use that as a swap. First right-click on the swap partition and select "information", and copy or write down the UUID. Next edit /etc/fstab:

gksu gedit /etc/fstab

Remove any lines whose third field is "swap" (be conservative; if you're not sure what to do, leave a line alone) and add a new line like this:

UUID=uuid     none     swap    0     0

Replace those spaces with tabs, and replace the lowercase string "uuid" with the UUID you copied or wrote down earlier.