This works for KDE 3.x:

On your keyboard press ALT+F2 and then type kcontrol into the input
field, then, press [ENTER].

Now you have started the KDE Control Center, and from here you'll be able to install icon themes. On the left bar select : Appearance & Themes->Icons.

Here you can choose between installed themes and install new ones.

Note: Many people make the mistake of unpacking packages, this is wrong, the icon installer expect to open a compressed package files that usually have extensions like: *.tar.gz , *.tgz, *.tar.bz2

The short and simple answer to all
these questions is: Yes, you can. The longer answer is: Yes,
you can, if you comply with the appropriate license.

The first version of the Crystal Icons was created by Everaldo. Later others
joined, among them the highly productive Torsten. They are licensed under the
LGPL. To prevent possible misunderstandings an add-on is added to the license
notice:

This copyright and license notice covers the images in this directory.

Note the license notice contains an add-on.

**************************************************************************

KDE Crystal theme icons.

Copyright (C) 2002 and following years KDE Artists

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation,

version 2.1 of the License.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    **** NOTE THIS ADD-ON ****

The GNU Lesser General Public License or LGPL is written for software libraries

in the first place. We expressly want the LGPL to be valid for this artwork

library too.

KDE Crystal theme icons is a special kind of software library, it is an

artwork library, it's elements can be used in a Graphical User Interface, or

GUI.

Source code, for this library means:

 - for vectors svg;

 - for pixels, if applicable, the multi-layered formats xcf or psd, or

otherwise png.

The LGPL in some sections obliges you to make the files carry

notices. With images this is in some cases impossible or hardly useful.

With this library a notice is placed at a prominent place in the directory

containing the elements. You may follow this practice.

The exception in section 6 of the GNU Lesser General Public License covers

the use of elements of this art library in a GUI.

kde-artists [at] kde.org

++++++++++++++++++++++++++++++++++++++++++++   

Below is the text of the LGPL version 2.1

Krita is a (pixel-based) painting and image editing application for KOffice. Krita
is part of KOffice since 1.4. Krita contains both ease-of-use and fun features
like guided painting (never before has it been so easy to airbrush a straight
line!) and high-end features like support for 16 bit images, CMYK and even
OpenEXR HDR images.

Download a klik image of Krita then read the Krita Manual (in PDF format).

Karbon14 is a vector-based drawing application for KOffice. It allows
artists to create complex drawings without losing image quality when zooming in
on, or resizing the drawing. You can use Karbon to add finishing
touches to diagrams created using Kivio or charts created using KChart.
Graphic design ideas can be quickly and easily transformed into high
quality illustrations with Karbon.

The Open Clip Art Library (OCAL) aims to create
an archive of user contributed clip art that may be freely used. The
project's reason for providing this clip art is to make open source
applications more useful to users; for some users, the availability of
good clip art that can be quickly dropped into a document to dress it
up can be as important as any other feature in the application.

The project was started in early 2004 as a spinoff from Inkscape by
Bryce Harrington and Jon Phillips as a way to help consolidate SVG
images contributed by Inkscape users with similar collections from
other projects. It was directly inspired by the Sodipodi Flags Clipart
project from 2003. 

The Worldwide.KDE map shows the distribution of contributors to KDE
throughout the world. If you contribute to KDE in any way (developer,
artist, documentation, translations etc.), you are welcome to be listed
on the map. Please fill in the form.

If you like the contributor maps and would like to show your support for the KDE Project, please feel free to use one of the web images on your home page (remember to link it to kde.org).

Nathan Willis has written a very good article on Krita for linux.com, Exploring natural media graphics with
Krita, where he describes where Krita developers want to take Krita in the future.

Of course, Krita is and will remain a competent image manipulation application, with cmyk,
lab, adjustment layers and all that jazz, but their core interest is indeed natural media.

Developer, Bart Coppens has managed to make wet paint usable. In this image you can also see Gábor and Casper’s jointly produced layer preview tooltips.