DMG Segments problem


Ok, I have downloaded the Developer Tools.
19 segments of the tools are now on my disk.

But how do I install this?
The extention is DMG.1 ... DMG.19

OS 10.1 says it is a document but it is a segment of a large DMG.
How can you make 1 DMG from these segments and install it?

many thanks
You need to use Stuffit Expander to rejoin the files....a no brainer that took my hours to figure out!!!!