What legal steps need to be taken to restore ownership...?

If we are talking about the loss of such a legal document as a certificate of ownership of immovable property, the owner must contact the authority that issued the relevant certificate and obtain its duplicate.

In the event that it is not possible to obtain a duplicate certificate (the body that issued the certificate has been disbanded/reorganized/liquidated), the owner must apply to the court for recognition of ownership of such property. In this case, the legal document will be the court decision.

In case of loss or damage of a legal document, certified or issued by a notary, upon written application of the persons on whose behalf or in relation to whom the notarial act was performed, the notary shall issue a duplicate of the lost or damaged document.

If it is not possible to obtain a duplicate document certifying the right of ownership, the owner of the property may file a lawsuit in court for recognition of the right of ownership of such property, as provided for in Article 392 of the Civil Code of Ukraine.