chaedayoung The corresponding Service Channel (store or online) you will apply to will inform you about the cash out. It usually is a one time charge but there should be an ongoing promo where cash out can be paid in installments via credit card:
Purchase your iPhone 6 at 0% interest up to 24 months via our partner credit cards: American Express, BDO, BPI, Citibank, EastWest Bank, HSBC, Metrobank/PS Bank, PNB, RCBC Bankard, Security Bank/Diners Club, and Unionbank.*
*Standard Chartered Bank offers 0% interest up to 12 months only.
from: iPhone 6 Plans and Offers | Postpaid - Globe Telecom - under Light and Easy Payment
Best to ask the CSR at the store or the online agent who will contact you about the actual cash out. A word of caution though: stocks are very limited.