important measures before terminating the webservice provider

Our webservice provider was doing good job but now a days they started charging too much for maintanence and SEO and also now we require to revam our website with many additional features for this we have got the proposal from them which is heavily over priced. hence we have decided to terminate their services and look for the new server provider.
We have identifed the new webservice provider , what all the necessary measures to be taken before terminating the services from the exsiting provider. Please help by providing the list of important things to be done.