Renewing a Michigan CPL is substantially the same process as applying for your original CPL.  Basically download the application from the MSP website and take it to your local sheriff's office (you can fill out the application, but don't sign it yet- it must be signed in the presence of an official).  If your fingerprints are stored electronically from a previous application you're not required to get fingerprinted again.  The renewal license fee is the same as for an original, currently $105 for 5 years i think.  You don't have to take a new class, but  the application has a section for renewals where you certify you have spent at least 3 hours reviewing the pistol safety course and current laws, and 1 hr of range time in the preceding 6 months.