First of all, go to any driving center in Singapore, register an user account, apply basic theory test, book a date and pay an exam fee around SGD6+ by using NETS only.
Most importantly, pass the test. Get a piece of pink sheet from Traffic Police counter: Application for A Driving License to Drive. You need it to know what is the document requirement for driving license conversion.
Next, go back to your hometown to ask for retrieval of driving license record. In JB, you can either go to UTC or JPJ.
1. You must have all copied documents on hand in order to LET information counter issue queue number to you.
2. You can renew your Msian driving license to Max 5 years. It will last until its expiry date even though you convert to Sporean driving license.
3. Queue number of driving license renewal and request for record retrieval is different.
4. Photocopying at JPJ is MYR0.30 per front page per item. Meaning if you request to photocopy license, NRIC and SG NRIC on one page. It still cost you MYR0.90.
Of course there is always a hidden process available which may save you more time. The offer starts from MYR250.
Then next step is go back to Traffic Police counter to convert to Singapore driving license ^^ go luck to all.
Update:
I went to Bukit Batok Driving Center for license conversion. I strongly suggest you reach there before 830pm and get queue number. Be ready with original and photocopied documents: Singapore IC, Malaysian IC, PR permit entry, passport, Malaysian license, JPJ document and a passport size photo. After officer reviewed your document, you are asked to watch a safety video on 1st floor. There are sessions held at 1015AM, 1115AM and so on. After watched the video, the officer there will return you the slip with a stamp to acknowledge your completion of video-watching. Bring it back to the counter for final processing! Upon payment of SGD50 via nets, you will receive a slip telling you that you can drive and your new license will be posted to your home within a month!