For your own use, you can type anything you like, modify it in any way that you like. There are no restrictions on that sort of thing, as long as it is strictly for personal use. Among other reasons, a copyright holder would have no knowledge on which to base a case and no particular incentive to make a legal case.
The problems would occur depending on what you mean by "share it". Within in a small research group there would likely be no copyright violations (likely "fair use"). Putting in on a website without the copyright holder's permission is almost certainly a violation.
The question of when "sharing" becomes "re-publication" can be a bit subtle, but the balance is probably more with the copyright holder. Translations and derivative works are protected under most copyright laws. One of the considerations in most copyright law is what is the effect on the value of the original. Things that reduce the value, which your ideas would seem to do, are normally violations.
It might be worth talking to the original publisher. They might be interested in what you want to do, and hold the rights to enable it. You could wind up with your name on the cover, along with the original author(s).