Replace part # 55506-AE010-B0.

Fiement:
2004 Toyota Sienna
2005 Toyota Sienna
2006 Toyota Sienna
2007 Toyota Sienna
2008 Toyota Sienna
2009 Toyota Sienna
2010 Toyota Sienna

Installation instructions:
Either leave the glovebox in place or remove it by pushing the sides inward and then pulling down and out.
Use a short Phillips screwdriver to remove the two screws then the unit will pop right out. You will then need to remove the lock from the assembly.
The lock has small clips that keep it in place so simply stretch the clips out with a small screwdriver and the lock will pop out.
Push the lock into your new assembly and reinstall it into your glovebox using the original screws.