Toyota Repair: Sienna key problem, sienna minivan, toyota sienna

Question
The ignition key in my 1998 Toyota Sienna Minivan will not turn. No previous difficulty: worked fine one evening, would not turn the next morning. Thought at first the steering wheel was locked, but it wasn't. Key will turn @1/8th inch, enough to unlock steering wheel, but no farther. Checked all fuses, brake interlock, etc. with no luck. Do I just need to replace the switch or are there other sources for this problem? Thanks.

Answer
The lock cylinder needs to be replaced, the key has to be able to go to the "acc" position to release the retaining pin on the lock housing otherwise it has to be drilled out, if you can get it into the ACC position and want to try do replace it yourself let me know and I will try to explain how to do it, if the key can't be put into the acc position I would recommend having the toyota dealer do this.