There is a very good and detailed description of the whole building process at Build a Microscope
The A1 mini is a great little printer, I also have one of those and printed my microscopes with it. Printing the ofm microscope works fine with the standard settings, only “Slice gap closing radius” for the brim needs to be set to 0.001.
@hendry thank you for coming by the stand. Each version of the microscope has a different bill of materials. In the link that @rootboi posted, go to the instructions and select the microscope version that you plan to build. The version with low-cost optics is a good place to start and is simple to upgrade to other versions. The build instructions for that version will show the detailed bill of materials. If you want to get the right things easily, the OpenFlexure web page has a list of vendors who sell parts kits or sets of the nuts, screws and lenses that you will need.