Hi Luis,
You can erase part of the page by two methods:
1. Open the uploaded note and click on Edit --> Edit Note
A new window (Edit Note) will open. Now click on Tools --> Selector.
Now using the Selector tool, select the area you wish to erase and click the cut button.
You have now successfully erased part of the note.
2. Open Note and convert
In Myscript window, click conversion --> Ink Editor
In Myscript Editor window, you can erase portions of the page by using the eraser tool.
I hope that the above answers your query.
Arvind Joshi