Remove an instance from SQL 2008 R2 cluster

I need to uninstall DB1 from a 2 nodes, active-active SQL 2018 R2 cluster. Instance1 on DB1. Instance2 on DB2

From what I have gathered, I need to move Instance2 to DB1, then run the SQL setup.exe to remove the passive node, DB2. The uninstall process does not interrupt the Instance1 and Instance2 on DB1, is that correct?

 If the uninstall failed, will Instance1 and Instance2 on DB2 still be able to serve the data?

Thank you very much.