There is an easy way to change any screen field you see on the screen. SE16N.. Joke..
We can create LSMW with the transaction we want to use to change specific field. Let’s say we want to change some field in PA30 or PP02. First of all we need to point the system to a specific record. So let’s enter exact date into begda and endda to allow system to choose exactly that record. Click on Copy button so it would fill all fields with data from the database record. Change one field you wanted to change.
And here is a trick. When you return from LSMW recording to Edit recording screen there will be a set of fields you saw on the screen. Delete all of them except that one you want to change (and have changed). It means system will change only one field, not all fields with some values from a file.
It took me 10 minutes to record this LSMW, thus it’s pretty convenient way to do mass changes.
LSMS Delete Screen Field