diff --git a/src/myftp/client.py b/src/myftp/client.py
index 96dbf91..21e0c52 100644
--- a/src/myftp/client.py
+++ b/src/myftp/client.py
@@ -119,17 +119,30 @@ class Client:
                 # change command handling
                 elif change_command_pattern.match(command):
                     command_name, old_filename, new_filename = command.split()
+
                     print(
                         f"myftp> - {self.protocol} - Changing file named {old_filename} into {new_filename} on the server"
                     ) if self.debug else None
 
+                    first_byte = (change_request_opcode << 5) + len(old_filename)
+
+                    second_byte_to_n_byte = (
+                        old_filename.encode("ascii")
+                        + len(new_filename).to_bytes(1, "big")
+                        + new_filename.encode("ascii")
+                    )
+
                 # unknown request, assigned opcode is 0b101
                 else:
                     command_name = None
                     first_byte: int = unknown_request_opcode << 5
 
-                # get or put case
-                if command_name == "get" or command_name == "summary":
+                # get change put cases
+                if (
+                    command_name == "get"
+                    or command_name == "summary"
+                    or command_name == "change"
+                ):
                     payload = first_byte.to_bytes(1, "big") + second_byte_to_n_byte  # type: ignore
 
                 elif command_name == "put":
@@ -139,9 +152,6 @@ class Client:
                         else first_byte.to_bytes(1, "big")  # type: ignore
                     )
 
-                elif command == "change":
-                    pass
-
                 # help case and unknown request
                 else:
                     payload: bytes = first_byte.to_bytes(1, "big")  # type: ignore
diff --git a/src/myftp/server.py b/src/myftp/server.py
index a66bb99..0ac9b2c 100644
--- a/src/myftp/server.py
+++ b/src/myftp/server.py
@@ -138,6 +138,14 @@ class Server:
                             filename_length_in_bytes, req_payload[1:]
                         )
 
+                elif request_type == "change":
+                    rescode = self.process_change_req(
+                        filename_length_in_bytes, req_payload[1:]
+                    )
+                    filename_length_in_bytes = None
+                    filename = None
+                    response_data = None
+
                 elif request_type == "unknown":
                     rescode = rescode_fail_dict["unknown_request_rescode"]
                     filename_length_in_bytes = None
@@ -188,6 +196,51 @@ class Server:
 
         return request_type, filename_length_in_bytes
 
+    def process_change_req(
+        self, old_filename_length_in_bytes: int, req_payload: bytes
+    ) -> int:
+        old_filename = req_payload[:old_filename_length_in_bytes].decode("ascii")
+        new_filename_length = int.from_bytes(
+            req_payload[
+                old_filename_length_in_bytes : old_filename_length_in_bytes + 1
+            ],
+            "big",
+        )
+        new_filename = req_payload[old_filename_length_in_bytes + 1 :].decode("ascii")
+
+        actual_new_filename_length = len(new_filename)
+
+        try:
+            if new_filename_length <= 31 or actual_new_filename_length <= 31:
+                old_filename_full_path = os.path.normpath(
+                    os.path.join(self.directory_path, old_filename)
+                )
+                new_filename_full_path = os.path.normpath(
+                    os.path.join(self.directory_path, new_filename)
+                )
+
+                print(
+                    f"myftp> - {self.protocol} - Changing file named {old_filename_full_path} to new file {new_filename_full_path}"
+                )
+
+                os.rename(old_filename_full_path, new_filename_full_path)
+
+                return rescode_success_dict["correct_put_and_change_request_rescode"]
+
+            else:
+                print(
+                    f"myftp> - {self.protocol} - New file name longer than 31 characters error"
+                )
+                return rescode_fail_dict["unsuccessful_change_rescode"]
+
+        except Exception as error:
+            traceback_info = traceback.format_exc()
+
+            print(f"myftp> - {self.protocol} - {error} happened.")
+
+            print(traceback_info)
+            return rescode_fail_dict["unsuccessful_change_rescode"]
+
     def process_summary_req(
         self, filename_length: int, req_payload: bytes
     ) -> Tuple[int, Optional[str], Optional[int], Optional[bytes]]:
@@ -335,7 +388,7 @@ class Server:
             # help case
             elif filename is None and response_data is not None:
                 first_byte = ((rescode << 5) + len(response_data)).to_bytes(1, "big")
-            # unsuccessful cases
+            # other cases
             else:
                 first_byte = (rescode << 5).to_bytes(1, "big")