You can request NVC for an expedite if your parents case is still Documentarily Qualified (if it is not, you will need to update their documents first to get the case back into DQ status). After the expedite request, NVC will forward your request to the US Embassy in Manila and from there you can wait for their response - likely the Embassy will approve it because you have waited so long. Only then will NVC forward your parents case to the Embassy.
from there you have a couple of options:
1) You let the Embassy to schedule your parents interview. In this scenario, there is no telling when you will get that date - the experiences of folks are different - some take days, weeks or, months. I am hopeful that they will get to you much quicker.
Or, 2) you can check the NVC visa status: https://ceac.state.gov/CEACStatTracker/Status.aspx
if it is READY - you can create a CGI account and schedule the interview yourself.
In either case, once you have a date, you can schedule the medical exam - which must be completed before the interview.
