Follow this tutorial if you have knockout competition with multiple stages (as round) and want to switch to a new Rounds format available in v0.10.0
Supposed that you have something similar to the screenshot below: multistage competition with stages as rounds.
Modify existing competition (main stage). Set multistage to “no” and create new rounds populating them with appropriate teams.
Go to the Secondary stages and rename unlinked competition (for fast search). In Matches column you can see a number of matches in this competition.
Go to the Matches list and filter by league and season. Here you can change a match structure from our renamed competition.
Change structure and save Match data on the next screen to recalculate statistic.
Remove empty competition. Check the number of matches is empty and remove it.
If you change all matches but forget to resave match data, go to the Service links and recalculate statistic for all matches.
Repeat steps 1-3 if needed.