Here is a template from what the navy of The Philippines have done with their own Hamilton-class ship by way of having her upgunned. These details have been provided by a Filipino Beegeagle’s Blogger, Max Montero.
(..)Initially the ex-Hamilton class ship BRF Gregorio del Pilar PF 15 was armed only with the 76mm gun but was later modified in The Philippines with the addition of the following weapon systems;
– a Mk.38 Mod 0 Bushmaster chain gun aft (previous position of the Phalanx which was deleted by the Americans prior to delivery)
– 2 x Mk.16 20mm cannons, and
– 6 x 12.7mm machine guns.
(..) Only yesterday, 9 September 2012, the Philippines Navy announced plans to install Harpoon missiles on both Hamilton class ships, while the US Department of Defense confirmed the sale of 2(nos) Mk.38 Mod. 2 Typhoon 25mm chain gun systems which would be installed on either Hamilton-class ship, although no word yet on how they intend to do it, either on the fantail where the Phalanx was previously installed (1 each ship) or both will be installed on the ex-USCGC Dallas which was handed over to the Philippines Navy last week and has now been renamed “BRP Ramon Alcaraz PF-16”