PDF converter - not creating a clean copy

I work with an all comers orchestra and need to create parts for instruments not usually in a traditional orchestra. If a piano accompaniment/part is available, I will work from that music to create a new part or take a cello part and turn it into a baritone sax part. I converted a piano part pdf into a .msz file and the measures weren't even; it's full of invisible markings and every file I have converted has a tempo at quarter note = 120. What is the simplest way to get a clean copy or clear all the little plus signs on the bars, etc. Thank you.