How do you format an external HD

[viconi]

I have a external HD that was used for time machine that I am going to erase because I now have a time capsule. I was able to erase part of the HD but it is still showing 138 out of 500 gigs used. No data is visible when I open it in finder but when I click on info it shows that space is still taken up?

How do I view the 138 gigs of data?
How do I delete it?
If these two things dont work how do I format the HD?

Thanks

 

[MM07]

Have it connected to your Mac and use Disk Utility. Then you can erase and reformat it.

 

[viconi]

Thanks for the help, worked great?

 

[MM07]

No problem.