Ask your mobile carrier for a SIM replacement or SIM swap
Verify your identity with the carrier
Request that your existing number be moved to the new SIM
Provide the new SIM card details if required
Wait for the carrier to activate the new SIM
Insert the new SIM into your phone
Restart your phone
Test calls, texts, and mobile data
Keep the old SIM until the new one is fully working
Contact the carrier again if the number does not transfer correctly