You fill in the form; photocopy all the pages of your damaged passport; complete the payment form; make an appointment at VFS/The Trendy (Sukhumvit soi 13); take it all to them.
I can only speak for my own case, but no they have never queried it or told me he needs to do it (he's 5 now, but has had an annual Extension since he was 1).
That is completely wrong. The IELTS Life Skills A1 and B1 test is only testing conversational English and listening skills. For A1 level the grammar required to pass is very basic. Far more important is the interaction between the two candidates and the examiner.