My 1.5 year old MacMini refused to read optical discs.
Apple asked me 80EUR for the repair evaluation because the warranty expired.... a way too much according to me for a product supposed to be of quality.
I bought the basic repair kit on iFixIt to get the required screw drivers and followed the instructions to get to the optical drive.
Just cleaned the lense with alcohol.
No need for the specific opening tool for MacMini.
2 screw drivers are OK to open the case.