well... seeing as I am here.....
I've just bought a ts and the halyards need replacing. The spinnaker halyard runs inside the mast. I was thinking of replacing this myself to save some money. Is this a tricky thing to do? I was thinking of attaching the new halyard to the old and pulling the line through the mast that way. I'm just new to boat ownership and never done this myself. Always had the privilege of going out on someone else's boat... now the bills stop with me!

Also, can I just use line bought from a hardware store, or does it need to be a "marine quality" or something similar?
Thanks.