Use your fingers!

Thoroughly wash hands, dump kefir and what its done to the milk into a strainer over a bowl - and fish around in there with your fingers to get the grains out. Metal shouldn't be used, it can damage the grains.
That's what i do and its never hurt the grains.
The yellowish liquid will drain through the colander and you'll be left with the yoghurty consistency kefir - yummy to eat like that, or drain it in cheesecloth overnight and you've got soft cheese the next day!

Check out Dom's kefir site - it pretty much has everything you EVER wanted to know about kefir on it.

xoLeah.

http://users.chariot.net.au/~dna/kefirpage.html