You can edit and re-post your blog...
When press Publish, you can find an option..
Just don't tick the option.. Then it will be goes a mail to everyone who get a notification for that..
And about the changes, you can do one thing..
Suppose you had written "This is my first blog"
And now you want to change the sentence "This is my second blog"
Then you can write like that
This is my first blog This is my second blog..
In than way, others can see the changes in the same screen...
And in title, you can add a in last as like "(Updated on 15.03.2014)"
Now explain the reason in comment portion...
So that other can see the reason also..