Rửa sạch mực bằng xà phòng và nước. Xoa bơ hoặc bơ thực vật lên vết mực. Dùng túi trà đã pha và để nguội xoa lên vết mực.

Given the above summary, write a detailed text in English for it.
This is probably the easiest and most accessible solution. If the ink is oil-based, as many ballpoint pens are, you may not have much luck, but if the pen uses water-soluble ink, it should wash off right away.  Water-based inks tend to seep through paper and take longer to dry, so they are more likely to smear and get on your skin.  Roller ball pens and some gel pens are usually water soluble. It will be kind of gross and may get messy, but the oils in these products will help dissolve the oil contained in the ink. Dissolving the ink will bring it to a liquid state, and when you clean off the butter or shortening with a dry paper towel, the ink should start to come off. This same principal means that oils like coconut oil, baby oil, or olive oil will also help dissolve the ink. Pour some oil onto a paper towel and use it to scrub off the ink. After making yourself a cup of tea, set the tea bag aside and allow it to come to room temperature. Once cooled, scrub the ink with the tea bag. It should rub off easily.  The oils in the tea, combined with the rough fabric of the bag, will work together to break down and lift the pen off your skin.  Don't be too harsh when you rub the tea against your skin, or you may break the bag and spill tea leaves everywhere.