I have a lightning and every time I take it out I have to step the mast and take it down. It really isn't bad, but there are a few tricks that help, assuming an aluminum (not wooden) mast.
1. Don't step the mast yourself unless you have a mast hoist. I did this and dropped it on my friend's roof. When I bought my mast I watched the elderly gentleman I bought it from do this like it was nothing. He had some tricks, but I prefer not to mess with it.
2. Prepare the mast before you put it up, get all the shrouds laying out beside it just as if it were already up. Make sure the forestay is in the front, backstay in the back, etc. Use rigging tape or electrical tape to tape around the plugs that go into the spreader so that if they don't come out and allow the mast to snap.
3. Prepare the inside of the boat so that the mast can just slip right in and you don't have anything to snag on.
4. Use the trailer tire or a friend's foot positioned at the butt of the mast while "walking" the mast up until it is vertical. Once the mast is vertical it is very easy to keep that way unless you let it start leaning.
5. Have a friend balance the mast while you hop up on the boat. Make sure you place a life jacket on the deck so you can rest the mast down later if necessary.
6. Have your friend hold the bottom of the mast with both hands close together. You stand on the boat and keep your hands far apart on the mast. This allows you to control the mast while your friend simply lifts STRAIGHT up. As the mast goes up, make sure that it stays vertical. As you get it over the boat, slowly move it over the opening, making sure to keep it vertical. This takes some coordination with your friend but after you've done it a few times it gets easier.
7. As you lower the mast in, again, insure you don't snag on anything and that it fits snugly into the step. Once it is in, connect the forestay and it will be able to stand on it's own.
There are several ways to connect the shrouds, but insure they are the proper tension (or close).
To take down the mast, do the same in reverse.
For more info check out:
Welcome to the International Lightning Class
The tuning guides will help alot. As to leaving the mast stepped, if you can do it, then do it! But, don't let it scare you. The Lightning is a great boat and a blast to sail.
Where are you sailing from? There are Lightning fleets all over and someone there will be happy to teach you to set up your rig.
Good to see other Lightning sailors on Sailnet!
Andy