How to change an hashtag in an instagram post

I accidentally misspelled an hashtag in one of my IG post and I need to modify it or my pic will be held out from an hashtag competition i want to partecipate to.
Is there a way to do it?

The hashtag is in the first comment and i've already hit the 30 limit.

Please help!

Don't think this is possible

Actually I managed to do it simply by deleting the hashtag comment and posting it again with the correct hashtag.
Usually Instagram doesn't allow this, but this time it worked without problems. I got lucky maybe