Hi! I booked business class seats one way on SQ and TG using my United miles (Gold elite).
The routing is TG flight HKG to BKK (overnight lay over of 16 hours) then TG flight BKK to SIN (layover 2 hours) then SQ flight SIN to MNL. The tickets have all been issued for travel on Dec 2013.

My question:
1. I wanted to stay longer in BKK maybe a layover of >24 hours, can I change the time of the flights? Leaving HKG morning, and departure from BKK afternoon/evening? No change dates for the issued tickets only flight times.

2. Since the flights are TG and SQ, how do I proceed if I want to change the flight times?

Thank you in advance!