Updating migration link

Author: kelbrown20

installing/installing-preparing.adoc

@@ -44,9 +44,9 @@ If you want to use {product-title} but do not want to manage the cluster yoursel
 [id="installing-preparing-migrate"]
 === Have you used {product-title} 3 and want to use {product-title} 4?
 
-If you used {product-title} 3 and want to try {product-title} 4, you need to understand how different {product-title} 4 is. {product-title} 4 weaves the Operators that package, deploy, and manage Kubernetes applications and the operating system that the platform runs on, {op-system-first}, together seamlessly. Instead of deploying machines and configuring their operating systems so that you can install {product-title} on them, the {op-system} operating system is an integral part of the {product-title} cluster. Deploying the operating system for the cluster machines as part of the installation process for {product-title}. See xref:../migrating_from_ocp_3_to_4/planning-migration-3-4.adoc#migration-comparing-ocp-3-4[Comparing OpenShift Container Platform 3 and OpenShift Container Platform 4].
+If you used {product-title} 3 and want to try {product-title} 4, you need to understand how different {product-title} 4 is. {product-title} 4 weaves the Operators that package, deploy, and manage Kubernetes applications and the operating system that the platform runs on, {op-system-first}, together seamlessly. Instead of deploying machines and configuring their operating systems so that you can install {product-title} on them, the {op-system} operating system is an integral part of the {product-title} cluster. Deploying the operating system for the cluster machines as part of the installation process for {product-title}. See xref:../migrating_from_ocp_3_to_4/planning-migration-3-4.adoc#migration-comparing-ocp-3-4[Differences between {product-title} 3 and 4].
 
-Because you need to provision machines as part of the {product-title} cluster installation process, you cannot upgrade an {product-title} 3 cluster to {product-title} 4. Instead, you must create a new {product-title} 4 cluster and migrate your {product-title} 3 workloads to them. For more information about migrating, see link:https://redhat-cop.github.io/openshift-migration-best-practices/01-planning.html[OpenShift Migration Best Practices]. Because you must migrate to {product-title} 4, you can use any type of production cluster installation process to create your new cluster.
+Because you need to provision machines as part of the {product-title} cluster installation process, you cannot upgrade an {product-title} 3 cluster to {product-title} 4. Instead, you must create a new {product-title} 4 cluster and migrate your {product-title} 3 workloads to them. For more information about migrating, see xref:../migrating_from_ocp_3_to_4/index.adoc#migration-from-version-3-to-4-overview[Migrating from {product-title} 3 to 4 overview]. Because you must migrate to {product-title} 4, you can use any type of production cluster installation process to create your new cluster.
 
 [id="installing-preparing-existing-components"]
 === Do you want to use existing components in your cluster?