This is a good article with a detailed description of the cermony:
New Agong installed
. . .Present to attend the Installation Ceremony of Seri Paduka Baginda Yang Di-Pertuan Agong Al-Wathiqu Billah Tuanku Mizan Zainal Abidin was His Royal Highness Prince Hj Al-Muhtadee Billah, the Crown Prince.
Accompanying His Royal Highness the Crown Prince to the Installation Ceremony was Prince Abdul Qawi. The rich royal traditions and customs of the installation ceremony were on display at the Balairong Seri or the Throne Room of the Istana Negara.
. . .arrival of Tuanku Mizan, 45, and Tuanku Nur Zahirah, 33, to the Throne Room, led by the Datuk Maharaja Lela Tengku Farouk Tengku Jalil and bearers of the 'Cogan Alam' also known as the 'Mace of the Universe' and the 'Cogan Agama' known as the 'Mace of Religion'.
Borneo Bulletin
Tuanku Mizan Zainal Abidin Installed 13th Yang Di-Pertuan Agong
KUALA LUMPUR, April 26 (Bernama) -- The Sultan of Terengganu, Tuanku Mizan Zainal Abidin, 45, was Thursday installed as the 13th Yang di-Pertuan Agong in a ceremony steeped in custom and tradition of the Malay rulers at Balairong Seri of Istana Negara.
. . . The Yang di-Pertuan Agong, in his pledge inscribed in Jawi on a goat hide, vowed to govern the nation with utmost fairness in accordance with provisions in the Federal Constitution and uphold Islam.
Tuanku Mizan said he would ensure a just and peaceful administration.
After His Majesty read out his pledge, a nafiri (trumpet) was sounded followed by the beatings of the nobat (drum) "Raja Bertabal" (the King has been installed) by the Royal Terengganu Nobat Group.
This was followed by a 21-gun salute by the 41st Artillery Battery Regiment followed by the rendition of "NegaraKu" by the Royal Armour Corps.
Bernama