Agreed with Dennis. I did this recently on my 1995 272, and you just pull the center channel out (start at an end at the stern, and the rest peels right out). Before removing it, make some kind of mark right at the tip of the bow, so that you can be sure you put it back in evenly. Also consider marking the port and starboard ends. I found it surprisingly difficult to sort that out when putting it back on, despite the bends in the material.
When you do remove it, you might seize the opportunity to clean it up well. It won't always go back in exactly the same way, so any discoloration on the either side will show up a bit awkwardly.
Also, don't leave it out for long. It shrinks quickly (matter of days). I left mine out for about two weeks, and it turned out to be a full foot shorter when I put it back in.
Anyway, all of the above refers to the center channel only. As for the rub-rail itself, I would not recommend removing it entirely, but rather just removing 5–15 screws at a time, and working in sections. Putting the whole rail back in place could be a real pain without a second set of hands, and again you face the risk of it shrinking on you.
Finally, consider using something like LifeSeal to seal the screws that you're tightening up. (Just a dab in the hole or on the screw itself can do the trick.). This can save you some frustration later on when you might discover leaks in the cabin or elsewhere. I also found that some of my screws had stripped, so I moved up to a size 10 screw for a tighter fit on those holes.
