20 minutes - 2 hours
I had used this Mac to test various drives including SSD, they didn't always fit and over time the cable had become damaged next to the connector.
Finally it would no longer recognize a disc drive present.
Repair was easy to do , I followed the guide on ifixit to take apart the case.
Lots of tuny screws but was able to replace cable without much trouble.
stash all the little screws in baggies and label them so you know where they go when you need to reassemble. go slow.