Autodesk Revit Architecture

[#1]

I created many sheets with a wrong border, can I reassign another  titleblock instead of making all new sheets from scratch?

[#2 · Accepted solution]

Yes. Click on the Titleblock in a Sheet, then in Properties you should be able to select another Titleblock Family--which should be loaded into the Project first.

[#3]

Thanks! How did I miss that?

[#4]

and if you did many sheets: right click on one and choose Select All Instances, and then choose another loaded titleblock from the Type Selector in Properties.  No need to do them one by one.