Add PowerShell one-liner and uninstall instructions for all platforms

Getting Started/Install_Monitoring_Agent.md

@@ -15,11 +15,24 @@ Installation takes about 2 minutes and does not require a restart.
 
 ## Windows
 
+### Option 1: Download and Run
+
 1. Open this link in your browser: **[go.dbits.ca/rmm-win64](https://go.dbits.ca/rmm-win64)**
 2. A file will download automatically. Run it.
 3. If prompted by Windows Defender or SmartScreen, click **More info**, then **Run anyway**.
 4. The installer will finish on its own. No further action is needed.
 
+### Option 2: PowerShell Command
+
+1. Open **PowerShell as Administrator** (right-click the Start menu, select "Windows Terminal (Admin)" or "PowerShell (Admin)").
+2. Paste this command and press Enter:
+
+```
+irm go.dbits.ca/rmm-win64-ps | iex
+```
+
+3. The installer will download and run automatically. No further action is needed.
+
 ---
 
 ## Mac
@@ -68,9 +81,39 @@ No automated changes, updates, or monitoring will occur until a technician has r
 
 ---
 
+## Uninstalling the Agent
+
+If you need to remove the agent, follow the steps for your operating system.
+
+### Windows
+
+1. Open **Settings** > **Apps** > **Installed Apps** (or **Add or Remove Programs** on older versions).
+2. Find **Tactical RMM Agent** and **Mesh Agent** in the list.
+3. Click **Uninstall** on each one and follow the prompts.
+
+### Mac
+
+1. Open **Terminal** and run:
+
+```
+sudo /usr/local/mesh_services/meshagent/meshagent -fulluninstall
+sudo launchctl unload /Library/LaunchDaemons/tacticalagent.plist 2>/dev/null
+sudo rm -f /usr/local/bin/tacticalagent
+```
+
+### Linux
+
+1. Run the same install script with the uninstall flag:
+
+```
+curl -sL go.dbits.ca/rmm-linux | sudo bash -s -- --uninstall
+```
+
+---
+
 ## Need Help?
 
-If you run into any issues during installation, reach out to us:
+If you run into any issues during installation or removal, reach out to us:
 
 - **Email:** hey@dbits.ca
 - **Phone:** (506) 404-0055