My extension to stay based on retirement ends beginning of september. My question is: When i renew it, can i change it so it will end in November instead?

How do i do that if possible?

The only way you can change the date your extension is due is to got out for a non-o visa and apply for a new extension during the last 30 days of the 90 day entry from it.

Immigration will not do it nor is there a way for them to do it.

Ok, thank you Ubonjoe