I don't have a link, but will describe the process. This works for line repairs, too.
-Insert a needle with a fairly blunt tip (fly tying bodkin often works) into the core of one side of the line where you want to splice, about 1/2 inch, farther if this is a heavy line for heavy fish. A nice, clean, square cut will facilitate this. You might find it easier to use a smaller needle first, let it stay in a while to stretch the line, then go to the larger needle and let it stay in a while.
-Strip the coating from the other piece of line for at least 2 inches, more if the splice will be longer. I use acetone for stripping (dip the end into the acetone and let it soak for 20-30 seconds (longer with really tough coatings, like the one SA uses on Mastery lines), then use your finger and thumb nail to pull off the coating cleanly. Let this piece dry thoroughly--doesn't take long.
-Fray the end of the stripped core for 1/2 inch or so. Divide the frayed end into two equal (more or less) sections and cut off one section.
-Here's the fun part--pull the stripped core into the hollowed line end. There are various ways to do this. I don't always use the same method, depending on how well or poorly the process is going, and you might come up with a new and better way. You need to run the needle through the core and pvc of the line at the 1/2 inch point (like doing a needle knot leader connection). You may be able to pull the needle all the way through with the frayed core end inserted into the eye of the needle. I usually have trouble with this, so my favorite alternative is, after running the bigger needle or bodkin through the side of the line, I insert a slighly smaller needle through the line, starting at the puncture and out through the end, with a 12 inch length of 2X or 3X tippet inserted halfway through the needle eye, so that I am left with a doubled length of tippet, loop first, sticking out of the end of the line (and a needle inconveniently hanging from the loop). At this point, I take some cutting pliers and sacrifice the needle (covering the operation so no pieces go flying). Then I carefully pull the looped tippet back through the line (having inserted the frayed core into the loop).
-Mix up some 5 minute epoxy, coat the core with epoxy, making sure it is saturated for the last 1/2 inch next to the pvc, and pull the core into the hollowed line all the way until the outer pvc skins meet.
-Roll the joint to spread the epoxy around inside, cut off the protruding core cleanly, and wait for the glue to dry. Voila!
You might want to practice on some old line first--I never did, but then I headed off to Navy OCS in balmy Newport, RI, in December 1981, without asking the recruiter too many questions about what I was getting into, so that tells you my risk acceptance level (or intelligence level, more likely).

Regarding your friend's reel. Even if you make the line shorter so it will fit, it will be rolled too tightly around the small arbor and will result in nasty coils in that end of the line. If he insists on using too small a reel, may I suggest that he store his line in loose loops off the reel (the way you're supposed to store silk line) and only reel it up when going fishing. This will help a bit and reduce the amount of stretching needed before casting.

[This message has been edited by cross creek (edited 23 May 2006).]