First you need to do a
This will disable swap spaces listed in fstab. Then use a tool like parted to resize the partition.
This is your choice to select the tool. parted is available in RH/Fedora systems by default.
After you resize the partition then
Here replace hda4 with the name of your swap partition device. Then
If you did was resize this would work. But if your editing changed the device name, you might have to change the /etc/fstab.
All these can usually be done without the need of rebooting and without changing runlevels.