Quotes from VOA news:
"The disbursement will take place and it will take place on time," said Venizelos.
The Greek government still must carry out highly unpopular austerity measures before eurozone countries approve another installment on Greece's first bailout package.
Without the $10 billion disbursement, Greece says it will run out of money by mid-October.
1.What do the two "disbursement"mean?
Definition of "disbursement" by Longman is pay out money from a large sum that is available for a special purpose.so the first dibursement I assume means Greece will pay out it's debt on time. I'm a little bit confused about the second one,does it mean Greece paying out debt or eurozone countries paying out bailout funds for Greece?
2.what does "installment" mean?
Installment normally means a periodic payment a borrower makes to a lender, but it does not seem so in this news,it seems to mean an installment loan.
Who makes the disbursement will be clear only from more context than you have provided.
An instalment (BrE) is simply one of a series of payments. The payments do not have to be from a borrower to a lender.