Improve Application Gateway HTTP header rewrite PowerShell documentation

- Enhanced technical accuracy and clarity in component explanations
- Updated prerequisites section with detailed requirements
- Improved PowerShell code examples with better structure and comments
- Added comprehensive verification steps for rewrite rule removal
- Updated ms.date to 07/09/2025
- Improved Next Steps section with additional resources

Author: Vyshnavi-MSFT

articles/application-gateway/add-http-header-rewrite-rule-powershell.md

@@ -109,25 +109,27 @@ Set-AzApplicationGatewayRequestRoutingRule -ApplicationGateway $appgw -Name $req
 Set-AzApplicationGateway -ApplicationGateway $appgw
 ```
 
-## Delete a rewrite rule
+## Remove a rewrite rule (Optional)
 
-To remove a rewrite rule set from your Application Gateway configuration:
+If you need to remove a rewrite rule set from your Application Gateway, use the following steps:
 
 ```azurepowershell-interactive
 # Retrieve the current Application Gateway configuration
 $appgw = Get-AzApplicationGateway -Name "AutoscalingAppGw" -ResourceGroupName "<rg name>"
 
+# Remove the rewrite rule set association from the routing rule first
+$requestRoutingRule = Get-AzApplicationGatewayRequestRoutingRule -Name "rule1" -ApplicationGateway $appgw
+
+# Clear the rewrite rule set reference
+$requestRoutingRule.RewriteRuleSet = $null
+
 # Remove the rewrite rule set from the Application Gateway
 Remove-AzApplicationGatewayRewriteRuleSet -Name "LocationHeaderRewrite" -ApplicationGateway $appgw
 
-# Get the request routing rule and clear the rewrite rule set reference
-$requestroutingrule = Get-AzApplicationGatewayRequestRoutingRule -Name "rule1" -ApplicationGateway $appgw
-$requestroutingrule.RewriteRuleSet = $null
-
-# Apply the configuration changes
+# Apply the changes
 Set-AzApplicationGateway -ApplicationGateway $appgw
 
-Write-Output "Rewrite rule set 'LocationHeaderRewrite' has been removed successfully"
+Write-Output "Rewrite rule set removed successfully"
 ```
 
 ## Next steps