If the node whose specifications need to be changed is accepted into the cluster for management, remove the node from the cluster and then change the node specifications to avoid affecting services.
After the specifications of a node configured with CPU management policies are changed, the node may fail to be rebooted or workloads may fail to be created. In this case, see What Should I Do If I Fail to Restart or Create Workloads on a Node After Modifying the Node Specifications? to rectify the fault.