As of December of 2018, you can renew your CPL online at the State of Michigan website. The cost is the same ($115) but it might save you the time of having to go to the clerk’s office, and you can pay by credit card. The county clerk (where your permit was last issued) is supposed to mail you a renewal notice (by first-class mail not less than 3 months or more than 6 months before). The letter will have instructions and a renewal PIN that you will need to access your account online.
If you don’t get your letter and you are within the 3-month timeframe, you can call the clerk’s office and ask them to send a replacement letter.
Once you have started the process, the system appears to allow you to leave after each step and come back into the system without starting over.
Of course, your final step is to pay … and (once your payment clears) you should receive an email with a link to your receipt that you will need to download and print (last image). When I paid with a Visa card on a Friday I didn’t get the receipt until the following Wednesday even though the card was charged Friday.
This receipt becomes an automatic extension to your permit if you don’t get your new one before the old one expires, as long as you did apply before the old one expires.
Your new permit won’t be valid until your birthday, so you will need to carry both to be safe until the old permit expires.
Here’s what the process looks like: