Apologies for being such a numpty, but my son has a broken derailleur on his Hotrock 24. It has Shimano revoshift twist shifter and a Shimano SIS derailleur on a 7 speed block. My daughter’s hotrock has a Tourney derailleur but looking around, it looks as if an Alivio derailleur may suit (haven’t bought it yet).
My problem is how do you get the cable into the shifter? I’ve looked here and it doesn’t seem to explain in simple terms. Any help appreciated.

http://www.parktool.com/blog/repair-help/shift-levers-shifters

Might be of no useful info – sram XO has a tiny rubber window you flick open, removing the cable is easy – however I could only get in a brand new cable in, which importantly has a soldered sealed end. ANY cut cable just caught and re caught on the journey in.

Wally

Brilliant. Thank you, Drac. You’re a gentleman.
Edit: Thanks also Wally

No worries Parktools site is excellent for checking on bike repairs.