Ok done it.
Not too bad at all really.
Here is a run down for others.
Steps
Remove battery cover
Two screws hold the whole thing together, one is visible the other is behind the QC label
Once these are removed, you need to work the casing out from top to bottom with a little wiggle and slide.
The TOP part holds a spring and a cap, be careful not to lose these.
Once out the head is held onto a little plastic locator, pull it gently out.
The atty head has a pin that is held together with the a white wire and an insulator, its this we need to change.
I use an old insulator from an old atty for a protank.
Now this does not fit properly so I used the remaining white one from the original to act as an insulator and added the new one over the top of the pin and pushed this in.
Inside the casing are your buttons, so make sure you dont lose these (only 2) 1 firing and 2 linked together for the up/down modes
Once you have the insulator back in place push the pin back down.
If you are struggling for space the board is held on by two screws and these can be removed to give you a little more room.
Once you are happy, pop the buttons back in place and make sure they are in correctly and wont move when putting back together, the larger one tended to jump out for no reason
Now pop the atty head onto the locator from where is came from and then pop the spring into the little brass holder and place the plastic cap back ontop of the spring, look for the locator hole so as not to trap the negative wire.
Before you do, just check that the little white buttons on the board are working correctly, mine seemed to stick on the firing one as the button moved and pressed onto it.
Now holding the spring cap, slide this back in first, then the bottom part, remember the buttons so dont tip it up.
Once in place pop a battery in to check its on and then add an atty to see if you get a reading.
Once all happy just pop the screws back in and away you go.
Hope it helps.
Next time I will take piccys.
