Actually I meant neither.
When you apply for the LTVP, you will have a FIN number given. You don't "change" the EPEC for the LTVP. You need the EPEC, which is given by MOM, in order to apply for the LTVP. You still have the EPEC after you are given the LTVP. The EPEC only guarantees that you are academically pre-qualilfied "in a related industry". The LTVP only gives you an extended period of time to find an employer who can justify hiring a foreigner. Approval is a two part process. An EPEC holder has completed half of the process as long as it's a position in a related industry. The other half is the employer justifying the need to hire a foreigner in the first place (therein lies one of the biggest problems at the moment) So, holding a degree in Business Administration might not be enough to get you a job as a Mechanical Engineer, or as a Site Civil engineer.
It doesn't make any sense to try to apply for the LTVP from your country as it defeats the purpose of giving it out. It for those who are serious about trying to find a job here. As you have had the EPEC for a while now, and still haven't done anything, frankly, it wouldn't surprise me if ICA didn't give you an LTVP at all (figuring that you were all that serious as you've not been pursuing it vigorously). ICA is NOT required to give you a year long LTVP. In fact, even if you have an EPEC, they don't have to give you a LTVP at all. But you need the EPEC to apply for the LTVP. We've see some given 3 or 6 months, other's 12 months and a couple no LTVP at all. So the ball is in your court. Go for it, or don't. Keep stalling and forget it.
