If your brother who is one of your father's executors moved into his property and now refuses to leave now that your father has died can he be forced to vacate?

A person who occupies land or property and not being the tenant or tenant holding over after the termination of a tenancy who has entered into or who remains in occupation of the property or land without a licence or the consent of the person entitled to occupation is a squatter in possession and has a good title against all but the true owner whose right may be barred by lapse of time and you will have to begin summary proceedings for claiming possession as against squatters