The advice given in the 2 posts so far looks great. I would add one thing, however. You must use only wire nuts rated for CU/AL connections. NOT all wire nuts are rated as such. In fact, I just looked at the label on the bag of my favorite wirenuts (IDEAL Beige Twister) and it says specifically: FOR CU/CU CONNECTIONS ONLY. I know IDEAL makes a special wire nut for CU/AL: Model 65, Purple Twister. It's UL Listed for CU/AL connections.