Main menu:
Skype/MSN
Important - If your phone firmware version is earlier than v1.01.00 then you first need to install this file before the fimware upgrade itself:
http://rapidshare.com/files/86972277/wip330_sbe.bin
Assuming you are running firmware version v1.01.00s or later then all you have to do is follow the procedure outlined for firmware upgrading and instead downgrade to firmware version v1.01.00 which you can get here
http://rapidshare.com/files/86603479/wip330_v1_01_00.bin
If you want to follow exactly the route I and are using firmware earlier than v1.01.00 then I would advise you to upgrade first to version 1.02.12S and then you can downgrade to version v1.01.00 after first manually configuring Skype. However, you can almost certainly, as most people have, just downgrade directly to v1.01.00.
Most users will downgrade and be able to run Skype with no problems. An unfortunate few - who knows why - will find that the downgrade does not install all the required files. Elsewhere on this website you will find how to reinstall them manually but be aware that sometimes the new files do not survive a reboot.