Actually it is not that hard a job if you use your wits about you. I did this task on a Hunter 380. But it is not inexpensive. First, you need the line--double braid will work fine. I also bought Brion Toss' CD on splicing line. It has a number of different splices--find the one you want (I believe it is called an in-line splice) and watch it several times. I also bought one of Brion's splicing wands and I do think it makes a difference. I also bought the book that Brion has published so that I could refer to something that wasn't moving. You'll also need some sewing line and a needle. The latter is important as a friend of mine also did this task but failed to sew the ends like Brion suggests and his line came apart.
Okay, that is the sane response to your questions. You can quit now from reading further....
What really happened... I measure the line and bought the replacement at West Marine for about $60 (I'm rounding off here), plus the tape (Brion didn't have a CD at the time) for $29, plus book for $20 plus wand for $50. I go home and watch the tape and on the third watching the tape player eats my tape. Not a problem--I can take the machine apart and extract the tape which I do. I fix the tape, but the player back together and run it one more time.
Then I go to the boat with my stuff. I sew the new line onto the old and reeve it through so that the new line ends are in the cockpit. That was probably the only thing that went correctly. I then laid the book out so I could follow my notes and started to pull the inner lines from the outer line. Not a problem but when I wanted to put the outer in the inner (read the book or watch the CD) it wouldn't go smoothly like Brion did on the tape. I struggled and I pushed and the damn wand breaks. So back to West Marine and I buy a new wand ($50) and back to my house to watch the tape one more time. I watch it and the machine eats my tape. I take player apart and extract tape which is now ruined. Back to West Marine to buy new tape. ($29) (They love me at West Marine in my town) On my way home I buy a new tape player (top of the line $300) and watch new tape. FINALLY, I see where I have been making a mistake-I am pushing through the outer into the inner instead of pulling through the outer into the inner. I finally got the damn line spliced and sewn. Don't forget to sew or you'll do it all over again.
There was one more purchase that probably should go here as well. I did buy a small black and white 12 volt video with tape player that I could use on the boat instead of running back and forth from house to boat. But it was a bargain as they were closing them out at $179.
I also tried new words at the line, the wand, the tape and the book, plus I said interesting things about Brion's heritage. However, the final package of some $500 has made me a humble man. I think I can screw up just about any job on my boat. My wife says it is cheaper to have the professionals come over and do the job. And they do it faster.
Truly I wish you well.
Especially since there are only two boats in the whole state that have furling mains.... 
