update doc

en/_sources/mc.md.txt

@@ -20,3 +20,5 @@ mc -d /tmp/output /tmp/ClassA.java /tmp/ClassB.java
 ```
 
 After compiling the `.class` file, you can use the [redefine](redefine.md) command to re-define the loaded classes in JVM.
+
+> Note that the mc command may fail. If the compilation fails, the `.class` file can be compiled locally and uploaded to the server. Refer to the [redefine](redefine.md) command description for details.

en/_sources/redefine.md.txt

@@ -36,6 +36,26 @@ redefine /tmp/com/example/demo/arthas/user/UserController.class
 * `mc` command to compile the modified code
 * Load new bytecode with `redefine` command
 
+### Tips for uploading .class files to the server
+
+The `mc` command may fail. You can modify the code locally, compile it, and upload it to the server. Some servers do not allow direct uploading files, you can use the `base64` command to bypass.
+
+1. Convert the `.class` file to base64 first, then save it as result.txt
+
+    ```bash
+    Base64 < Test.class > result.txt
+    ```
+
+2. Login the server, create and edit `result.txt`, copy the local content, paste and save
+
+3. Restore `result.txt` on the server to `.class`
+
+    ```
+    Base64 -d < result.txt > Test.class
+    ```
+
+4. Use the md5 command to verify that the `.class` files are consistent.
+
 
 ### Restrictions of the redefine command