Need to merge two HD partitions into one

I have an external HD that has 2 partitions on it. I would like it to be a single partition again. How would I do this?

You need to use an application called Disk Utility which comes with every mac, just do a spotlight search for it.

Ok, to clarify I have disk utility open, I see that I can erase them or restore them, I see no option to make them on partition. Can you be more specific in what I need to do?

Yh, sorry...
Open up Disk Utility, with the External HD Connected.

Click on the External HD's name (Click on the HD itself, not the volume, if your not sure which one is the volume just click both orange icons, and choose the one which has the partition tab to the right)

Click on the Partition Tab

From the drop down menu choose the number of partitions you wish to make, in your case you want one partition.

and then simply click on the partition button at the bottom.

CAUTION!!!: this will erase everything on your HD...

Thanks, that worked. I kept trying to click on the partitions.