Not sure if this has been covered before but this is my first time and what follows is how I did it and the mistakes I made. It was done on a DC05 but the reel in the DC08, DC19 is pretty much the same and could be in some other models.
So had a dead DC05 that turned out to have had a new YDK motor fitted, all be it a cheep 1600w copy
, problem was the power lead, all twisted and split with no continuity when tested.
First thing prise out grey switch thing and remove rubber wheel on the left.
Turn over and remove centre cap
Then remove the 2 short wires, first noting where they fit (try to ignore the damage I caused, bit ham fisted)
CAREFULLY prise out the spring holder and disconnect the centre, don't let go until all tension is removed
Store this flat and with something weighty on it, just in case
I could not see any way to separate the reel, it was late and I was tired and I had had some wine and my eyes are the wrong side of 40
So, I followed the cable through the holes whiles turning the reel and disconnected the terminals.
This was as far as I could get so I cut the terminals off and pulled the wire out.
When I came to fit the new cable I figured out how to separate the reel, Squeeze the 2 tabs together and separate.
The above pictures show the way the reel turns and supply permanent power.
Next the silver thing (top right) has to come out, turn reel over and press tabs and push.
Now to fit new cable.
Because the new motor was 1600w I decided the 0.75mm cable originally fitted was not up to the job and went for 1.0mm, it fitted, just but after reassembling it was to heavy and you have to assist it back in, don't know if the fact that I used round cable rather that flat also affected this. Next time I will use 0.75mm cable.
So first thread cable into reel and around various grips.
Refit silver thing
I saved the original terminals as I didn't have any right angle ones and soldered them onto new cable and used shrink to insulate.
Connect to the terminals. Now while holding the spring connect the centre bit to the reel, and re fit spring holder making sure the marks line up.
Fit the 2 short wires and the centre cap.
Refit rubber wheel and switch.
Wrap the cable around the reel
Wind the inner part of the reel press the grey switch down at the same time so the spring moves from the outside to the inside, this is also how you tighten up the spring on a reel that's slow to rewind the cable. I fully tightened it as I realised the cable was going to be to heavy, with the correct cable you wont need to fully tighten it.
Pull out about 2 foot of cable and thread it into casing
Position reel as so
Refit top casing and then fit a plug and you can then test it and adjust the spring tension if needed.
It all works but the rewind is slow because of the heavy cable, but its all good, this DC05 will now become our decorating/car cleaning vacuum
Hope this helps someone.