I would send it to Spektrum too; unless your like me.
Between me and my brother we have been able to repair 3 failures in my DX8 over the years...
The first was a crack that mysteriously appeared in the right side gimble cage. It caused the stick to be pulled all the way down by the tension spring... I know some dummy knocked over the thing, but no one claimed responsibility.. Typical, HA!...…… I used CA glue and bonded the crack perfectly without ceasing the movement, whew!
Next up, I had 2 of those tiny tack tile momentary buttons fail. Both were for the roller clicker mouse controller. I took the unit apart and my brother was able to order a bunch of the switches from one of his parts sources for cheap. I got plenty of spares... We just de-solder the bad one from the PSB and replace it with a new one. However be careful, the conductive prints on the PCB are tiny and can be damaged easily by using to much heat in the soldering process...
Here's another thing I did to ease future service...
The green ground wire that connects the negative side of the boards to the case and neck strap hanging eyelet was modified so I only had to take the soldering iron to that connection once. Just solder an inch of small wire to the PCB first. Then connect the other side to the wire and insulate it with shrink wrap..
That way when you need to service the unit again, (and you will) you just remove the shrink wrap de-solder it there and leave the PCB alone...
Wish I could sent more detailed pictures but not at this time, sorry...