Read this thread:
http://www.gasgasrider.org/forum/showthread.php?t=12194
Pay no attention to the separator piston height dimmensions, as these were Sachs specific. Other than that it should be the same. I've done it successfully, messy but correct. You will want to get the needle for the Ohlins, as its much easier to assemble the resevoir side and hold the piston down with compressed air than manually while inserting the shaft/seal head.