This is how to reduce the number of characters displayed in a blog post on the default.aspx page of a blog site created from the OOTB SharePoint blog template.
- Open up the site in SharePoint Designer
- Open the default.aspx and switch to Code View
- Perform a Find & Replace for the following:
This would limit the number of characters to 99 and display the text contained in the MoreText attribute as the last characters. Check out this for more info on the Limit element.
Do remember to back up the page before attempting this just in case.... ;)