KEYFRAMES VALUE

You can't and that's the crux of it. Source text keyframes store absolute info and cannot be easily edited in bulk. You have to do it for each key individually. Otherwise of course there may be ways to set up your stuff more efficiently in the first place liek using multiple text layers or controlling parameters with text animators and expressiosn, but you have not provided any info about your project, so we can't tell you much.

Mylenium