The first thing you have to do (after the husk is removed) is to peel off the tough skin that coats the nuts, this is fiddly, but it is worth it so persevere.
Next step is to roast the inner nut in a shallow pan, the inner skin that coats the nut (similar to a peanut) can be left on as its roasting as it often falls off in the process. Keep roasting until the steam evaporates and the nuts start to gently brown.
Once roasted you can rub them gently in a cloth to remove and skin that is left, then put them in a container with a little salt, they taste wonderful and have a distinctive taste to other nuts that is quite delicious, if stored salted, in a jar, they will keep for a considerable time. Enjoy.