Any suggestions for covering part of a PDF document?

I have a hand-written document that I need to attach to an electronic customer report. There is information on the hand-written document that the company doesn't want the customer to see. Normally, I scan the document to a PDF and attach it, but hiding the information is the tricky part.

1) I can't use market to cover it up due to company rules against using markers.

2) We only have Adobe Reader, and I won't be able to buy any of the Adobe writers or any other editing software.

3) I have tried adding the document as an image to MS Office documents, but the conversion leaves the handwriting illegible, especially when I would have to print it and scan it again to get it into PDF form.

4) I'm stuck actually cutting out pieces of paper to cover the information I don't want passed, and then scanning it again.

Any ideas?