Yesterday when to the CPF Maxwell Center after booking an appointment 2weeks earlier. The service is very good. Guide you start from you enter. Transaction is smooth and fast. Less than 1/2hr, all done.

Take the number and walk down to the basement on the left side. Wait for your call.

The document you need is
1) IC. If you register under an old IC, make sure you have an old IC particular. The IC number is important. He search your acc through IC number and name.
2) Passport.
3) Bank letter if you want TT money back. Go to the bank counter, and tell them the CPF particular need. Make sure the letter have letterhead, your bank acc, name, Bank address and SWIFT code.
4) Your Email.

This is 3 important doc. Bring together like CPF statement and an old passport (that you work in SG) if have. In case they need an additional doc.

They will fill up the form for you in the PC. What you need is to confirm the filling is correct and sign. They will photostate your IC, passport, and Bank letter.

You can ask them to print out the latest statement. But it didn't reflect the final amount. Cause this yrs interest hasn't been calculated into. The final amount is only available when bank in/ email to you.

The process will require 4 month to bank in the money. So probably I'ill only can get it end of Dec. But I think there is no hurry. Cause can earn more in interest if your money stays longer inside. 

It is not necessary to go to Maxwell Center if appointment is full. Choose other centers available at your preferred date. Maxwell Center probably is the nearest from the airport I guess. About 20min.

Sharing on my experience on the process but still waiting for them to reply.

The online form https://form.gov.sg/63573e845cfdb20012171772 basically didn't do anything but just check the eligibility to closure your account or not.
You can skip this if you know your are eligible. For me it is a waste of time since it took them about 6weeks to reply to us then just to tell us to submit form and supporting docs as below.

There are a few ways to get CPF account closure
i) If you still have Singpass, you can use the My Mailbox to submit application. Most will not have this if you not SPR anymore
ii) If you still have personal POSB, DBS, OCBC or UOB register under your Singapore NRIC previously, you can submit the CPF form and all your supporting document digitally via
    this link "Write To Us"  https://www.cpf.gov.sg/eSvc/Web/FeedbackSubscription/Index. Details is located on the CPF Account closure form which you can download on CPF website
    --> my wife use this method since she still have an account there that was registered with Singapore NRIC
If you do not have both Singpass and account under Singapore NRIC as above, you will need to do mail or head to CPF office in Singapore physically\
iii) By mailing, you will need to get the form sign under witness from Singapore Overseas Mission (KL, JB or even other countries), appointment needed and the slot availability for KL and JB is till next year.
    - all supporting documents need to be certified too (ie. passports (new and old), ICs, Singapore NRIC, renunciation letter and etc...)
    --> I used this method and needs to pay fees for witness and certifying all documents. Once forms and docs sign and completed need to mail to address on the forms.
iv) Make appointment with CPF office in Singapore and head to office with your documents to get it done
    -- a couple of people here in this forum has done this and seem pretty quick and smooth process

Now it waiting time of 8-14weeks or even more. You can only enquire the status after 14 weeks using Whatsapp.
For submission by mailing hardcopies, I do not have any mail, email or sms on acknowledgement of if they received or not but for my wife that submitted through the "Write to Us" she got email acknowledgement that they received and processing the account closure.

Hope this helps.