Getting rid of ink on paper requires the purchase of special materials in order to safely remove the ink without damaging the rest of the paper. It is much easier to simply cover the ink with some type of correction fluid if that's an option. If you have used erasable ink, you can simply use a standard eraser to get rid of the offending marks. If the ink is permanent and must go, you're in for a moderate challenge.
Use a pair of gloves throughout this ink-removal process to protect your hands from the chemicals you will be working with.
Purchase hydrochloric acid, also called Spirit of Salts at some retailers. You can purchase the chemical in liquid or salt form from hardware stores and numerous online stores, including the Science Company.
Dilute the hydrochloric acid with water. To dilute the chemical, use one part hydrochloric acid to five parts water. The water can be hot tap water.
Using a cotton swab, rub at the ink using the hydrochloric solution. If it is an important document, you might want to test the solution on other pieces of paper before applying it to the important document. Test to see how neatly it removes the ink and to see if the strength of the solution needs adjusting.
Citric and tartaric acids mixed with water are also said to be useful in removing ink from paper.
Avoid using household bleach to remove ink from paper. While it removes ink, it often leaves a yellow residue.