You will need a crochet hook and a bit of crocheting knowledge, not more than how to make a chain. Make one loop on the crochet hook, hold it next to your knitting needle, yarn at the back.
Make a chain stitch over the knitting needle. It may feel a bit comfortable, but that's the way it works:
Then again, yarn at the back of the knitting needle, make a stitch over the knitting needle:
repeating the movement until you have enough stitches on your knitting needle. Make a few loose chains (which will make it easy to remove the caston when necessary) and cut the thread, pull the loose end through the last chain.
Now you can start to knit with the main yarn in these stitches.