Certificate rotation is a complex step by step procedure described in the docs as follows, click each link for details.
The following link provides a video guide for the above documents to show how to check the certificate type, expiration date and how to rotate the certificates.
Please note videos illustrate the procedure being done in OpsMan v2.7, please use the official documentation for up to date information on the procedure for newer versions.
More details about certificate rotation is available in the official documentation.