Potbelly, As you may know already, the rudder has a hole in both the front and back of the rudder about 4f inches down the rudder from the point of pivoting. The cord to raise and lower is attached on either end and looped thru the rudder box and out the top in a continuous loop. To raise, you pull on the cord from the on the outside (back of the rudder) and to lower you pull on the cord that comes out of the rudder box, then secure it in a cleat that covers the hole at the top of rudder. I found that depending on the about of sand and how tight my bolts are, the rudder can be sticky and sometimes as I am trying to pull my cord out of the cleat, its become somewhat tight but it seems to work well enough.

I use a large plastic button bolt to snug the rudder movement up tight so that it won't move up or down on its own.  To lower the rudder, I pull on the aforementioned cord.  To raise it, I just reach over with my hand, grab the aft edge of the rudder, and pull it to the up position.  It stays up, mainly because of the tightened button bolt, and also I suppose because wood floats.