There are a few options to finish the drying process. If you live in a warm, dry climate, you can lay them out in the sun. Place them on screens to allow airflow around the chipotles.
You can use a food dehydrator to dry your chilies. There is one draw back to this though. The smokiness of the chipotles will soak into the surfaces of the dehydrator, leaving it with a smoky flavor for days, or even months.
Lastly, you can finish off the chipotles in the oven. This will release a smoky aroma into your house for a day or two, but it won't be too bad. Set your oven to a very low temperature (below 200 degrees F) and spread the chipotles out on baking racks. Don't place them on a cookie sheet or pan, as this will impede the drying process.
Dry chipotles until they are completely brittle.