I'm assuming that you have a strap holding your boat on your trailer? Mine is about an inch and a half wide and winches down snug. That strap alone is probably enough to keep her weight on the rollers and the other bunk but I'm a little on the cautious side so I bought a couple of winching tie down straps at Fleet Farm. Each strap is rated at about 750 lbs. The main strap is way stronger than that. Leave the big one tight for both sides...One side at a time! Make sure the main strap is winched tight.
Add the additional two straps using the coach roof horn cleats to the trailer frame. Winch them tight.
(Just like you would be afraid to crawl under this boat if they weren't...)Top side:Bottom Side:
Now you can drop the bunk on the opposite
side from your straps.
When you are finished, jack the bunks back up snug. Don't over due it with the jack. Snug is all you want or you will have too much weight on the bunks and risk stress cracks! The bunks are more for balance than load. 90% of your load should be on the keel and about 5% on each bunk. Be sure your bunks are secure before repositioning your straps to drop the other side!