As we detail in this post about the new Mini macsIt is one of the good news of them that their two RAM sticks are SO-DIMM, accessible and replaceable by the user or, preferably, by specialized technicians.
These are standard DDR4 memories at 2,666MHz, meaning you don't have to pay the expensive eyes Apple charges to upgrade the RAM of the new Mac mini from 8GB to 16GB, 32GB or even 64GB after all, these combs can be found in the market for much fairer prices (and are gradually falling).
For those who buy a Mac mini and want to upgrade their RAM, have already painted three good guides on the web showing how to perform the procedure: one from iFixit, another from photographer Trung and one from the channel. Brandon Geekabit on YouTube, which you can check out below:
The whole process is relatively easy and takes no more than 10-15 minutes, but some specific tools are required (such as a TR6 Torx wrench).
What's cool is that, besides you can save money on the upgrade, you don't necessarily have to do it right now when you buy the machine. After a while, when you feel the need, you can upgrade RAM and give it a "new life".