Question about installing the non-free pakages

[Chan Min Wai <dcmwai@pl.jaring.my>]

    I want to install Kde from my contribe CD and the dselece said iit
need the qtd1 so I look for it in the non-free site and then downloaded
it.
    Now I have one question.

How to install this pakages and all the other pakages with xxxx.deb

Thank you.