It wont take longer then 30minutes to replace / exchange the cables - ignoring taking the tank off, loosening the cables and all that stuff to work easy and freely!
You need the following tools:
1) Take of the "funny" looking clamp that keeps the cables in their position - comes off easy - use pliers.
2) Start with taking out the upper cable, nipple comes off easy peasy, put on the new cable - job done 5min max! No secrets there straightforward to do!!!
3) The second cable is a little more work ... at the hand throttle end - shove the cable all the way towards the throttle assembly. This gives you all the cable you need to loop out the nipple. Then gently pull the cable free but watch where (location) you pull it out as it is tight and can easily get caught. That's where you need the flashlight!
4) Install the new cable in reverse order but remember where and how you pulled out the old cable. No big deal if you don't - it just will take you a little longer to route the cable correctly! I needed 3 trial (10-15 mins) - then I realised how exactly it by-passes the nicks and crannies in there (flashlight will help greatly - didn't have one<lol - another 5mins >).
Don't forget to shove the actual cable towards the throttle assembly agan so that you have plenty of cable to play with. Just put the nipple back in the slot (pliers to hold in position, screw driver or so to push it INTO the position)
5) Then the fixing clamp (which is delivered as part of the lower cable) needs putting back - all but 5 mins. Use pliers to hold in position and the screw driver or similar to poke into position.