In a strict technical sense, an MEID and an IMEI are distinct identifiers. You cannot simply "convert" an MEID into a functioning IMEI if the IMEI is already assigned to a different device. However, in the context of dual-mode devices (phones that support both CDMA and GSM/LTE), there exists a mathematical relationship between the two.

Convert the 6-digit hex suffix to an decimal number. Step 3: Combine and Truncate