jerrymaker

HI Ireceived a letter saying how many years I could pay to fill gaps in NI class3. I'm currently living abroad. 1.When I make the payment do I stipulate which years I'm paying for? 2.I already have 30 years paid so do I just need to pay 5 years of NI class 3 to make a full pension? 3. Can I pay in installments? 4. Can I pay by making an online transfer from my UK bank?