Honesty you would have to add an 'AFFIDAVIT' which is a legal document declaring the change in name to the certificate. You would have to visit any Ghanaian court to apply for the Affidavit.
NB: the name on your birth certificate must correspond to which ever name you want to change to.
THIS IS HOW TO CHANGE YOUR NAME IN GHANA
1. A person must possess proof, such as a birth certificate, of their current name. With this evidence the person must then take it to swear an affidavit before the Commission of Oaths, at a Ghanaian court.
2. Once this is done the individual must then go to the Office of the Judicial Secretary, where the affidavit is signed/endorsed.
3. For the third and final step the individual must have the changed names published in the Ghanaian Gazette. It is only after the new name is gazetted that it is considered legally changed.