Applied:
diff -ur a/file2 b/file2
--- a/file2
+++ b/file2
@@ -1 +1 @@
-file2 here
+modified file2 here

Updated buffer:
diff -ur a/file1 b/file1
--- a/file1
+++ b/file1
@@ -1 +1 @@
 file1 here
diff -ur a/file2 b/file2
--- a/file2
+++ b/file2
@@ -1 +1 @@
 modified file2 here