Sure, here are the steps to make a Spotify playlist available offline:

1. Open the Spotify app on your device.
2. Navigate to the playlist you want to make available offline.
3. Once you're on the playlist, you'll see a toggle switch labeled "Download".
4. Simply switch it on and your playlist will start downloading.

Please note that you need to be a Spotify Premium user to use the offline listening feature. Also, keep in mind that the songs are not actually downloaded in a conventional sense, they are made available offline within the Spotify app. This means you can't access them outside of the Spotify app.