Short answer: Open the file in Open Office, remove the protection then save.
Long answer (rant included):
So recently at work, we had a problem. One of the companies whose products we use sent us a data sheet for calculating values in a part as a Microsoft Excel spreadsheet. The calculations and internal functions however were password protected in the document. Personally, I think that’s a rediculous thing, to hide parts that the end user might need. So right away, I got to figuring out how to bypass it. Immediately, I started searching for Excel password crackers. Though I knew the risk of getting a virus and/or trojan was rather high, I was willing to risk it.
At the same time, the thought of opening the file in my favorite open source editor popped in my head. Open office opened the file without issue, and I went in to try to remove the protection, and what do you know? It didn’t bother asking for a password. So now I had in my sinister clutches the much better version of the file.
It really irks me that developers would think the people who would end up using their products are so stupid as to not be able to bypass any restrictions they put forward.
This is not the first time I had to do such a thing, and sure as hell won’t be the last. Just remember, if you, a developer of software or hardware decide to put a lock on something and you yourself can easily bypass it, then anyone who will end up using it will also be able to easily bypass it.