So I read everything about single handing and running lines aft but I still don't understand how you feed the sail. I have slugs on the main which makes life so much easier, but each slug must be hand fed into the mast in order to raise the main. What am I missing?
After you feed each sail slug into the mast, then there is another separate piece that is called a sail slug stopper. You put that in the mast track right behind the last sail slug and it has a screw knob that you tighten so that it stays firm to the mast. This holds all the slugs in place so that the slugs don't come falling back out. Some people use a small rope to tie around the bottom instead of a slug stopper. You can buy these at usually any boat store that sells to sailboats.
Repeating in different words, you load the main slugs into the mast during rigging, then never remove them until time to remove the boom and drop the mast. Otherwise they remain in the mast track, stacked above the slug-stopper. When you drop the mainsail, its top 2 to 3 feet remain attached to the mast, via slugs. In order to hoist it again, just pull the aft-led halyard.
Search on the word SLUGS (see a Search Link at top-center of every page). You can read through maybe a dozen earlier threads. You'll find pictures of a mainsail with slugs installed, and diagrams that show how the slugs are spaced along the luff. Feel free to post additional questions if the basics aren't clear.
I've lost one sail track stop, on my 26C(S), about 15 years ago. It's on the bottom off of Key West.
Remove the lock nut from the 1/4" horizontal hex head bolt, on the port side, near the front of the boom. Replace the lock nut with an eye nut. Attach a lanyard to this, and attach the sail track stop to the other end of the lanyard.
I couldn't get it to fit in the slot. Seemed like it was too big. (I face that problem frequently... )
Is there only one size of the round ones? It will be easier when I take the boom off and can get a little more leverage on a screwdriver to pry the opening a little wider.
So I read everything about single handing and running lines aft but I still don't understand how you feed the sail. I have slugs on the main which makes life so much easier, but each slug must be hand fed into the mast in order to raise the main. What am I missing? 
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