You wrap the line twice around the double ender, snap it into the hole on the spool (keeping it tight), and then toss the spool over the line twice, and snap the other end of the double ender back on your own line. This is the same as doing a jump. You can drop a non directional (or directional) marker on the side that you choose to exit so that your teammate knows where you went, and then change it if you hit a conflicting marker and turn around, depending on what you and your buddy decide.
Here's a video of the lost line drill from my class. 2:45 in you can see how to tie the reel in. It was during my class, and I failed to drop a non directional marker on the line at first, which is what the confusion is...I was wondering when I would get tapped on the head (the signal that the drill was over), and didn't realize what I was forgetting.
http://b.static.ak.fbcdn.net/swf/mvp.swf?7%3A136764=&v=528073356615&s=http%3A%2F%2Fstatic.ak.fbcdn.net%2Fswf%2Fembed.swf%3F7%3A134871&ts=http%3A%2F%2Fstatic.ak.fbcdn.net%2Fswf%2Fmvp_tail_slate.swf%3F7%3A134155
This should have been mandatory during your class (whether standards require it or not!), did you not do it?