To install the filter do the following in order.
1) Remove the existing IW(s) from the test module. Keep them together and make sure you keep the polarities straight. It doesn't affect the DSL, but some of your other telephony devices might be polarity sensitive.
2) Attach the filter leads and the IW that's homerun to your DSL modem. Tighten down the posts, but make sure you don't be a superman. Snug is plenty. You want to make sure that you don't damage the wiring.
3) Attach the other IWs to the filter and tighten down the posts. Again don't overdo it.
If you're using a different filter try to get it to fit nicely inside. Make sure that there's no bare metal that's exposed and that's it.
More to come