You can crack your password. You can use tools "Office Key 8.1" form http://www.lostpassword.com/
Office Key tools can found your password by entering in the background all possible character combination to your document.
This is an information on that Tools.
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Office Key recovers passwords for Excel, Word, Access, Outlook, PowerPoint, VBA files and Outlook e-mail accounts.
Browse (Ctrl+O) for the file, select from recent files list or drag the file to this window to start recovery.
Click Settings (Ctrl+T) to configure password recovery engine. Show settings.
Click Online toolbar button to instantly preview encrypted files content. Learn more...
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Our try use this tool.
http://www.download.com/Free-Word-Excel-Password-Wizard/3000-2092_4-10249515.html?tag=lst-1
Hope it can help you.