Hey Carole … I’ve replaced deck lines previously and its pretty easy. First step is to draw out how the current lines are setup on your kayak (so that you know how to install the new line). In particular note location and type of knots. 2nd step is to get some new line (your local kayak shop can probably sell you some). 3rd step is to install following the layout you drew from the original lines. Couple of things to consider / you might need:
- BBQ lighter to melt the ends of the line where you cut it.
- You may need to learn how to tie some specific type of knots (e.g. https://www.101knots.com/hangmans-knot-noose.html).
- You might need a 2nd set of hands to help you tighten the line.
I recommend looking online as well as there are a bunch of good resources about deck lines … e.g. https://paddling.com/learn/deck-lines-rigging .
Finally, if this is not your thing I would recommend your local kayak shop and I am sure they can do the work for you … e.g.
https://www.coastoutdoors.ca/ (North Van)