Hi Paul,
Are you concerned about PCs, or NPCs? PCs should retain everything except:
- Armor
- Vision (new system)
- Class Specific:
- Rogues will need to redo expertise skills (normal and proficiency will stay).
- Bards will need to check "jack of all trades" at the bottom. I believe their skills will work, but they may need to open their "Attributes and Abilities page" and remove "floor(@{PB} / 2)" from skills such as "acrobatics_prof_exp". They can clear the field's input or remove the field - either will work.
If you're concerned about NPCs the new sheets will not use the old data. I left the old data hidden at the bottom of the sheet if you want to manually copy them. Otherwise if you become a mentor I've written an
D&D 5e Shaped NPC Importer & Converter which will convert them for you for the most part.