It's a very wise idea to install a new steering cable. They come in different lengths of course, but otherwise they are pretty much generic.
This procedure is a rather simple change over. (two beers and it's done) Easier than a hip replacement! (well, not quite as much grease on everything as with the cable change over)
Make sure you have a few rags on hand, before you commence the surgery.
Simply unbolt/unscrew all the obvious bits on the steering assembly then drag out your original cable, lay it out straight, take a measurement of it's overall length and toddle down to your local Whitworth's store or ship chandlery. Better still, take your original cable with you in your "howdy" Watch out for all the greasy bits!
Better still, watch this video. Although, you may not have to remove the steering wheel and helm assembly unless it's on the way out as well.https://www.youtube.com/watch?v=VJ8UruO-_a0
I'm personally a big fan of hydraulic steering. A dream with high HP motors and multi rigs. The down side..it's more expensive and not really a project DIY for the layman to install.