Metagram

I was wondering if there is anyone who is good at modding who can teach me how to take the APC Tank FROM TBoGT and move it to the original IV (ie: getting the APC into the game with Niko as the protagonist?) I was successful in having the APC model in the game and even drove it around in the street, but the problem is the canon; it won't fire any shot and also the canon itself fails to rotate. Any leads and directions would be greatly appreciated.