We have researched this on the internet and came across a few mentions of removing ink text from paper.
There are different types of ink so it depends on what type of ink was in the pen. Removing the ink will depend on the solvent and vehicles used in the ink (which is similar to those in paint).
There are also different paper types. Some papers can be lightweight and damage more easily to any cleaning methods you try and others more heavyweight that may be able to withstand a more thorough cleaning such as what you are seeking help for.
Here is what we have found out for you.Baking Soda and Water:
1. Combine baking soda with water until you have a thin paste.
2. Using a clean white cotton cloth, dip this in the paste and apply it to the ink on the paper.
3. Rub or dab gently so you don’t damage the paper.
4. Allow the paper to dry.
If the above steps does not work or did not remove enough you can try the process again or try one of the suggestions below:
You can try acetone, this will work with most types of ink and can be purchased at your local home improvement store or if you only need a small amount you can purchase non-acetone fingernail polish remover.
You could also try ammonia then rinse with water.
Another option may be to use bleach then soak well in water to remove all traces of the bleach as it may leave a yellow discoloration. Do not combine the bleach and ammonia as this can create a harmful gas.
To apply any of these solutions follow step 3 above, just beware you will run the risk of damaging your paper.
If this is paperwork that cannot be redone, you may want to seek a professional who knows about restoring artwork or old papers for more advice.