Format external drive

Control or right click on it's desktop icon and select Get Info.

Caution: reformatting it will erase everthing on it.

What are you wanting to use the External HD for?

In order to reformat is this done in disk utility, under the RAID tab? Which type do I select if it is in the RAID section? Thanks!

Yes in Disk Utility, but using the Partition tab for a single Hard Drive.

Additionally you should "Start a discussion" of your own, instead of asking on a year and a half old thread.

My apologies - I thought it was better to use a relevant thread as opposed to start a new one. In the future I will start new discussions.