First I removed the old micowave and I installed the new one. If you are going to install DYI the spacer blocks need to have a large hole to connect from the top.
That said I have been enjoying the unit for 3 months. The convenience settings are great, just press a botton and it starts to run. Very happy with the cooking results as well. Works very well with frozen foods. Alarms are loud enough to hear , plus the digital screen alerts you that food is in the unit if you forget to check. Very heplful.