Am I in the right queue at immigration to change my ED visa to a retirement visa?

Okay, an update: success

Step 1: Counter N2 - Cancel ED extension of stay. Presented passport, termination letter from school and signed copies of relevant pages of my passport. Note, that termination letter from school should be on school letterhead, signed and stamped and should include start date, end date and effective end date. The effective end date is particularly significant as it determines what date you should be leaving the country. Anything past that date is overstay.

Step 2: Grab a ticket for L counter and then go downstairs and get another set of copies of relevant passport pages with new cancelation stamps, etc.

Step 3: Counter L - Grant new extension based on retirement. Presented passport, relevant signed copies of passport pages, notarized income affidavit from US embassy, the "three secret forms" and a hand drawn map of my neighborhood (not used).

Step 4: Counter A - 90 day report. Presented 90 day report form and passport.

Despite the initial hiccups on the first attempt caused by not having the appropriate termination letter from school, the process went smoothly. Thanks to everyone here for the solid information and support.

No, N1 is not the correct desk. Officer Pimpa indicated desk L1 then desk N2.

However my school did not provide the appropriate termination letter. I have a completion certificate but that was not deemed adequate. So I have to go back and make another run at it tomorrow once I get the appropriate documentation.