Updated v0.15 post-upgrade instructions

UPGRADING/v0_15.md

@@ -86,8 +86,26 @@ After the upgrade and migration complete, several follow-up steps are required o
 - **Rebuild search indexes**: All search indexes must be rebuilt to take advantage of the new indexing strategy. This can be done from the webadmin interface ``Manage → Maintenance``.
 
 - **Recalculate disk quotas for all accounts**: This step is **not required immediately**, but it is recommended to perform it at some point after the upgrade. The new version includes additional metadata in quota calculations, so recalculating ensures accurate disk usage reporting.
+    ```bash
+    $ curl -X DELETE https://myserver.org/api/store/quota/<account_name> -u <admin_user>:<admin_pass> -k
+    ```
 
-- **Delete deprecated spam classifier keys**: Remove deprecated spam classifier keys from the memory store. These are the keys starting with the integer prefixes `12` to `16` and `17` to `18`.
+- **Delete deprecated spam classifier keys**: Remove deprecated spam classifier keys from the memory store. These are the keys starting with the integer prefixes `12` to `16` and `17` to `18`:
+  - If you are using Redis:
+    
+    ```bash
+    $ for code in {12..18}; do
+        char=$(printf "\\x$(printf '%02x' $code)")
+        redis-cli --scan --pattern "${char}*" | xargs -r redis-cli DEL
+    done
+    ```
+  - If you are using your database as the in-memory store:
+    
+    ```bash
+    $ /opt/stalwart/bin/stalwart --config /opt/stalwart/etc/config.toml --console
+    > delete y\x0c\x00 y\x12\xff
+    > delete m\x0c\x00 m\x12\xff
+    ```
 
 ## Troubleshooting