There are basically two types of shroud extender (righting) systems.

The bigger boats, or boats with very tight shrouds, usually use Hyfield Levers in place of, sometimes in addition to, the normal shroud adjusters.
Smaller boats or boats with loose rigs can often get by with a simple cable shroud extender.
In order to use either system, the crew must be able to reach the shroud attachment and pull a pin.
This may involve climbing on the elevated hull or installing an access hole in the tramp.

Pictures and diagrams of these and other righting systems can be found in the Hobiecat catalog on page 18.
Or http://www.hobiecat.com/support/pdfs/18_19.pdf