Article in English: This method works best for printed ink and use only when you need to remove only a few letters. Hold the blade vertical to the paper and rub gently. Do not press the blade very hard on paper or you get off layers of paper. If you are using erasable ink, you can easily erase it with an ink eraser. Erasable ink is typically blue, not black, and will be identified as 'erasable' in its packaging. It's also often found like a pencil, with ink on one end and an eraser on the other.  If you aren't sure whether or not your ink is erasable, try erasing it with an ink eraser to find out. Gum erasers and rubber erasers work best on pencil/graphite, and are not recommended for pen. It's possible to erase ink using a vinyl eraser, but be careful. This eraser is very rough and can easily rub away the paper itself along with the ink you're erasing. Use a triple-ought (000) sandpaper and a small sanding block. If the ink removal requires you to manipulate the sandpaper more carefully than a small sanding block (or your fingers) will allow, cut off a small piece of the sandpaper and glue it to the eraser end of a pencil. Carefully rub the inky paper with your sandpaper using small lateral motions.  Be careful not to press down too hard when rubbing the sandpaper to the inky surface. Blow gently across the page to remove any small pieces of grit, ink, or paper as you work to better see your progress. A grinder is basically a mechanical application of sandpaper surface that may be able to sand your paper more evenly and easily than you can do it by hand. A Dremel type mini grinder with a slightly rounded stone grinding head is recommended.  Using a sander is particularly recommended for inky edges on books. A sander is often too rough for a paper's surface, unless the paper is quite strong.

Summary in Vietnamese:
Dùng lưỡi dao mỏng để xóa vết mực. Dùng gôm tẩy mực đặc biệt. Làm sạch vết mực bằng giấy nhám. Dùng dụng cụ mài có bề mặt mịn để tẩy vết mực trên giấy.