Update README.md (#856)

* Update README.md

Addressing #757

* Update README.md

README.md

@@ -238,31 +238,31 @@ run `python3 torchchat.py export`
 
 ### Deploy and run on iOS
 
-The following assumes you've completed the steps for [Setting up
-Executorch](#set-up-executorch) and
+The following assumes you've completed the steps for [Setting up Executorch](#set-up-executorch).
 
-Open the xcode project
-```
-open et-build/src/executorch/examples/demo-apps/apple_ios/LLaMA/LLaMA.xcodeproj
-```
-Then click the Play button to launch the app in Simulator.
+#### Requirements
+- Xcode 15.0 or later
+- A development provisioning profile with the [`increased-memory-limit`](https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_developer_kernel_increased-memory-limit) entitlement.
 
-To run on a device, given that you already have it set up for
-development, you'll need to have a provisioning profile with the
-[`increased-memory-limit`](https://developer.apple.com/documentation/bundleresources/entitlements/com_apple_developer_kernel_increased-memory-limit)
-entitlement. Just change the app's bundle identifier to whatever
-matches your provisioning profile with the aforementioned capability
-enabled.
+#### Steps
 
-After the app launched successfully, copy an exported ExecuTorch model (`.pte`) and tokenizer (`.bin`) files to the iLLaMA folder.
+1. Open the Xcode project:
+    ```bash
+    open et-build/src/executorch/examples/demo-apps/apple_ios/LLaMA/LLaMA.xcodeproj
+    ```
+2. Click the Play button to launch the app in the Simulator.
 
-For the Simulator, just drag&drop both files onto the Simulator window and save at `On My iPhone > iLLaMA` folder.
+3. To run on a device, ensure you have it set up for development and a provisioning profile with the `increased-memory-limit` entitlement. Update the app's bundle identifier to match your provisioning profile with the required capability.
 
-For a device, open it in a separate Finder window, navigate to the Files tab, drag&drop both files to the iLLaMA folder and wait till the copying finishes.
+4. After successfully launching the app, copy the exported ExecuTorch model (`.pte`) and tokenizer (`.model`) files to the iLLaMA folder. You can find the model file called `llama3.pte` in the current `torchchat` directory and the tokenizer file at `$(python3 torchchat.py where llama3)/tokenizer.model` path.
 
-Now, follow the app's UI guidelines to pick the model and tokenizer files from the local filesystem and issue a prompt.
+    - **For the Simulator:** Drag and drop both files onto the Simulator window and save them in the `On My iPhone > iLLaMA` folder.
+    - **For a device:** Open a separate Finder window, navigate to the Files tab, drag and drop both files into the iLLaMA folder, and wait for the copying to finish.
+
+5. Follow the app's UI guidelines to select the model and tokenizer files from the local filesystem and issue a prompt.
 
 *Click the image below to see it in action!*
+
 <a href="https://pytorch.org/executorch/main/_static/img/llama_ios_app.mp4">
   <img src="https://pytorch.org/executorch/main/_static/img/llama_ios_app.png" width="600" alt="iOS app running a LlaMA model">
 </a>