Relatively easy:
- Make sure you have a connection to a well-known ed2k server such as DonkeyServer 2.
- Search a bit for a well known file such as the aMule-2.1.3 source package, and download it.
- Wait for some sources indicated by the file.
- Go to the Kad page and click on "bootstrap from known clients".
- Make sure you have Kad selected in the preferences menu, this for future restarts.
This should start up Kad and connect you to peers.