Not sure what version you are on but I am pretty sure this is not possible, I have tried to do this many times, there seems to be no way beyond adding the new value and deleting the old. Hopefully you dont have a lot of templates and rules tied to the bad value. I have even tried to change case, that didnt work.

FWIW this is coming soon

It's actually already here. As I recall it was introduced (but not announced) in version 20.18.03 All you have to do is double-click on the value.

Note that if the value that has a typo is used in a workflow or business rule, you'll have to review those. Not sure if there are active defects around this.

but wait, DONT USE THAT though (i know it was there) - it wont work.  You will not be able to publish if it is tied to any business rule, workflow or field dependency.  I screwed up a container that way so be careful.    it might appear that it is working at first but then you go to publish and it will throw up all over you. 

Yeah be careful! - I tested this on a test server to change the case on a few choices, it blew it up. Basically wouldn't publish with tons of errors because I had field dependencies on the choices. It seems to work but doesn't fix dependencies, and i can't remember but it worked on either rules or templates. Overall it seemed to sort of work in a few places thats it.

Have you tried adding a new dropdown value and then using a Business Rule to update the older values?

Have any of you reported to BMC and received defect numbers? If so, can you please post. It's all nice to say it doesn't work and such, but without providing a defect number we can reference and send up ourselves, it doesn't help any..

I had to get help with this last week. I had 2 schools that combined into 1 school so I needed to update the name in the drop down. This can be accomplished by doing the following:

1. Add the correct name to the drop down

2. Create a time based rule to change incorrect spelling to correct spelling

3. After all have been moved over to new name, deactivate rule and you can now delete incorrect from drop down because there are no longer tickets associated with incorrect spelling. Hope this helps.

You can do this much quicker by just updating SQL directly. There's no audit trail, but that's generally not important for this type of work.