You will have to write to Bond Management team at email@example.com, informing of your intention and request for a letter of bond discharge with the following documents :
i. Colour scan Employment Certification Letter on official company letterhead stating the start and end date of employment.
ii. Income tax (Yearly IR8A/IR8E or Notice of Assessment for 6 years of bond service).
iii. CPF Yearly Statements (for SC/SPR).
iv. Any other documents as requested by your Sponsor.