Cordless Drill Repair - Add a Cord

So you are tired of dead batteries on your drill and do not want to mess around with replacing or fixing the battery.  Make the cordless sucker a corded drill.  Lots of people seem to think this is a good idea, so here is a guide to this technique.  If you have an instructable on this topic and I have missed it please let me know.  If you do want to fix the battery see the guide Cordless Drill Battery Maintenance .
Fixing good thrift-store powertools on the cheap  style
Here a drill and related tools are all adapted to external power.
Mains Power Tool Adaptor style
Here the power supply is rebuilt in the battery case.