Once Cleaning up the spec and the changed/removed styles are fixed, you can compare the old and new versions of a Part using the W3C HTML diff program. The following links use that tool to compare trunk with the current tr35/
Part 1: Core specification (languages, locales, basic structure)
Part 2: General (display names & transforms, etc.)
Part 3: Numbers (number & currency formatting)
Part 4: Dates (date, time, time zone formatting)
Part 5: Collation (sorting, searching, grouping)
Part 6: Related Information (supplemental data)
Part 7: Keyboards (keyboard mappings)
You will need to manually set the encoding in your browser to UTF-8 (and the tool still doesn't get it quite right). The w3c tool has many false positives (<pre> and <table> often fool it) also, so you will see cases like:
mappings—the mappingsâ€”the ability...
But it should allow you to double check that the Modifications are correct for your Part.