Server work for experienced MongoDB programmer

For our work, We have 2 separate parts to the project: 1) Repair a broken MongoDB Replicaset for our website, because the 3rd hosted server has been terminated. In order to do this, you will need to replace the 3rd server which is necessary for replica set to work, and change config for 2 production servers according to the new IP address for the 3rd server, as well as any other settings. 2) Repair 2 other development websites which have gone down (the website is down although the server is up, we likely need to restart some services and check if the server or database has been compromised, making any necessary adjustments and changes for the website to work properly)