This is the way I do it, The head is trimmed to 7" so the strings don't get wrapped up, and seem to flail the inside of the flue better,.
1- Attach heavy plastic sheet to end of flue tee with duct tape( I use old softener salt bags that I cut so I get a double layer) and cut a cross in it for sending the head and rods in to the flue.
2- Attach head and subsequent rods 1 section @ a time until all rods are attached stuffing them up the flue 1 section @ a time (take care to make sure they lock before attaching the next rod)
3-Attach rod adapter to drill (I use a 1/2" drive)
4-Start drill slowly and once the the head is rotating freely I go full speed and pull the away form the flue until I get to the section connection and then push back in then stop and reverse drill and do the same thing.( up down couple of times per rod section).
5- Repeat procedure for each rod section,removing sections as you finish each section of flue.
viola- chimney cleaned from the basement and dont have to climb a ladder until spring, hope this helps