Complicated ? - Just use an agent - simples ....
Renewed mine last week - here's what happened.....
8.20am, arrived at the bank just as they were opening .... updated pass book and got letter confirming 800k in bank ....
8.45am arrived at agents just as they were opening - signed form, handed over passport, bank letter and 8,000b ( 1,900 immigration fee plus 6,100 agents's fee) - had photo taken ...
next day at 4pm collected passport from agent ..... The fee includes the agent doing the 90 day reports and me not having to put a foot in the IO - best 6k i've ever spent) ...