You must have a SuperDrive, which is a floppy drive capable of writing to High Density floppies. If you have an old SE or Plus, you might not have this drive. Otherwise you should be fine. Next, you need to have a control panel called PC Exchange. If you have System 7.0 or higher, you can use this control panel.
All recent systems come with it installed.
If you don't, then your Mac will ask to reformat the disk. Eject the disk if it can't be read and look for the PC Exchange control panel or program. Turn it on if it's been disabled. The other piece of software you may need is MacLinkPlus from DataViz. This handy software has been bundled with the Mac Operating System for several years, so most users will have one version or another on their computer.