Comment 4 for bug 571361

How about this:
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Adding this PPA to your system

You can update your system with unsupported packages from this untrusted PPA by adding
ppa:jd-team/jdownloader
to your system's Software Sources.

Or from the Terminal (9.10 and above):
sudo add-apt-repository ppa:jd-team/jdownloader
sudo apt-get update

(Read about installing to 9.04 and older)
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Obviously substituting "ppa:jd-team/jdownloader" for what ever is the ppa.

This give the majority of users the command they need on the first page.
Users of older version can follow the link.