Simple clarification

I think 'and then' is better changed for 'and when' or 'and when later' to better clarify this sentence

book/07-git-tools/sections/submodules.asc

@@ -466,7 +466,7 @@ You have to do some extra steps if you want changes in a submodule to be tracked
 
 In order to set up your submodule to be easier to go in and hack on, you need to do two things.
 You need to go into each submodule and check out a branch to work on.
-Then you need to tell Git what to do if you have made changes and then `git submodule update --remote` pulls in new work from upstream.
+Then you need to tell Git what to do if you have made changes and when later `git submodule update --remote` pulls in new work from upstream.
 The options are that you can merge them into your local work, or you can try to rebase your local work on top of the new changes.
 
 First of all, let's go into our submodule directory and check out a branch.