Follow these simple steps to edit your teams:
1️⃣ Head to 'My Matches' and select the match under 'Upcoming Contests'
2️⃣ Click on 'My Teams' to the right-hand side
3️⃣ Tap the pencil icon on the team you wish to edit
4️⃣ Make the edits, save the changes, and that's it. 😀
PS: You can edit your teams as many times as you want, before the match deadline.