Few of my friends have visited Naran and Shogaran on CD 70.
Yes, it is right that CD70 have very weak engine to climb up on hill but with little modifications you can manage.
Replace the flywheel mounted on rear wheel, (connected with drive chain) with bigger diameter flywheel. This will slow down the speed of CD70 but increase power of it that CD 70 will climb hills easily. Also ask mechanic about drive chain, i think it be replaced too.
Remove chain cover.
Replace the breakshoes, use new breakshoes which are made up with fine leather which should not get heatup quickly. Beacuse on your way back you need frequent usage of breaks and too heated breaks may fail to stop bike.
On your way back, do not turn engine off, don't neturalize bike, use 2nd or 3rd gear to keep its speed under control.
Always keep rain coats with you.
Very important: before leaving offer two rakat Nafals and pray to Allah. Then everything will be fine.
Take care and enjoy.