The Sacrament of the Anointing of the Sick was instituted by Christ, though it was promulgated by the Apostle James.
Any one of you who is ill should send for the elders of the church, and they must anoint the sick person with oil in the name of the Lord and pray over him. The prayer of faith will save the sick person and the Lord will raise him up again; and if he has committed any sins, he will be forgiven.
James 5:14-15
The Sacrament can take place anywhere. It is given by either a Bishop or Priest as the ordinary ministers of the Sacrament. The Sacrament is made up of two main parts the laying of hands by the Priest and the anointing of the forehead and the hands while praying the words of anointing.
The Laying of hands shows that the sick person is the focus of the prayer and is a sign of calling down the Holy Spirit on the person to bring it’s gifts of healing and strength.
The anointing is with olive oil usually blessed by the Bishop at the Mass of Chrism. If the oil has not been blessed the minister of the sacrament can bless the oil himself. The prayer said during the anointing asks God to help the person with his love and mercy and to save and raise up those who are sick.