Not an Access expert but isn't TEXT limited to 50 chars as stated below?
Microsoft Access provides two field data types to store data with text or combinations of text and numbers: Text and Memo.
Use a Text data type to store data such as names, addresses, and any numbers that do not require calculations, such as phone numbers, part numbers, or postal codes. A Text field can store up to 255 characters, but the default field size is 50 characters. The FieldSize property controls the maximum number of characters that can be entered in a Text field.
Use the Memo data type if you need to store more than 255 characters. A Memo field can store up to 65,536 characters. If you want to store formatted text or long documents, you should create an OLE Object field instead of a Memo field.
Both Text and Memo data types store only the characters entered in a field; space characters for unused positions in the field aren't stored.
You can sort or group on a Text field or a Memo field, but Access only uses the first 255 characters when you sort or group on a Memo field.
Anyway, does the update statement work as below
ALTER TABLE t_document ALTER COLUMN Notes MEMO;
i.e. No square brackets?
True opening an EAP file in Access 2010 (without converting) allows you to query but changes to design are disabled

I guess if you could find an old version of Access that might work
Cheers
Phil