rewiring Avo two panel tester

[Bushbaby]

Firstly thanks, I'm glad I'm on the same wavelength as you guys but I have to say the wiring to mine looks very poor by comparision to photos posted

   

Is it safe to assume that I can use 24/0.2 hook up cable? I've tried unsoldering the existing cable from the 9 pin connector with little success...suggest that the Weller solder gun might be needed?

Thanks

Rob