Document how to switch to Prometheus's simpleclient

Closes gh-40993

spring-boot-project/spring-boot-docs/src/docs/antora/modules/reference/pages/actuator/metrics.adoc

@@ -549,7 +549,10 @@ If you use {url-micrometer-tracing-docs}[Micrometer Tracing], this will be auto-
 Please check the https://prometheus.io/docs/prometheus/latest/feature_flags/#exemplars-storage[Prometheus Docs], since this feature needs to be explicitly enabled on Prometheus' side, and it is only supported using the https://github.com/OpenObservability/OpenMetrics/blob/v1.0.0/specification/OpenMetrics.md#exemplars[OpenMetrics] format.
 
 For ephemeral or batch jobs that may not exist long enough to be scraped, you can use https://github.com/prometheus/pushgateway[Prometheus Pushgateway] support to expose the metrics to Prometheus.
-The Prometheus Pushgateway only works with the deprecated Prometheus simpleclient for now, until the Prometheus client 1.x adds support for it.
+
+NOTE: The Prometheus Pushgateway only works with the deprecated Prometheus simpleclient for now, until the Prometheus 1.x client adds support for it.
+To switch to the simpleclient, remove `io.micrometer:micrometer-registry-prometheus` from your project and add `io.micrometer:micrometer-registry-prometheus-simpleclient` instead.
+
 To enable Prometheus Pushgateway support, add the following dependency to your project:
 
 [source,xml]