Hello,
you have to open the Screen Editor, right click on "Library" (you find it on the right top in the Screen Editor) and then "Export Text Data".
You will get an .csv file with all texts in it. Change it and then Import the data. This also works with right click on "Library" and "Import Text Data".
In the past I get some troubles with the .csv file when i open the file in Excel and save it. It was not possible to Import it.
So it's better to make a copy from the exported file, change the text in the copy, afterwards open the exported .csv file with the Editor and paste the changes in the Editor file and save it.
Regards,
FStelzer