Get a net, costs less than ten dollars unless you are rural Australia and with the net you can try ebay or online stores, get the net and capture it, walking it inside your house. To train a bird they say it is good to feed it from your hand showing it that the hand is likeable for feeding them, but other than this, you really really will need to try hard to tame the budgie as it is not a baby anymore judging by your post.