Used a hyper sanitised racking cane and moved it from one keg to the other, while leaving the dispensing hose and valve connected to keep most of the funky crap in the tube.
It's been almost a week now, and it still tastes fine.
As I've pointed out on many occasion, I'm a noob, and I learn best by experience. So up to this point I didn't have a suitable socket wrench or a keg cleaning kit. I now realise the benefit to these, and will aquire both. Suffice it to say, I'm happy because my 'heart' transplant appears to have been a success.