Put it in the hole turn the disc side to side while giving it a slight wiggle. You will feel it slightly locate into the splines. From there either push the hub towards the gearbox or get underneath and get both hands on the driveshaft and push it in. It should slide in pretty easy, if its not going in or damaging the seals. Your not doing it right. Its not something that is difficult its more just a case of being patient and precise, hope this helps.