You must be in Co-op mode for this to work. One of the players must hold either direction at the character select screen. Then, the other player must rapidly press x to select a character. If you press x while the cursor is on a "locked" character, you will get a message saying the character is locked. This is where the glitch comes in. The characters are still rotating while the message appears, but the names don't change. As a result, Sam could have the name Gandalf under him. If you select the Sam character, the name will override the character and play as Gandalf. The second player may be able to select a locked character as well, depending on how many far the names rotated and which characters are available. Now you will no longer have to waste your time on the weak hobbits on Frodo's path. you can play through levels like Cirith Ungol as Legolas and Gandalf on the first try.