it's not hard, but you might need specialized tools for some things
you can buy BB installation/removal cups cheaply, make a headset/bb/bearing press with duct tape and chopsticks, but things like facing BB/headtube/brake mounts, which is often required, are better done by a qualified person with proper instruments
This frame has a pressfit BB, so no facing required. I also never had to face my brake mounts. Headsets on those chiner frame are most of the time the drop-in type so no need for any press there. You just need to tap the race on the fork with a PVC pipe or something similar. To me, the worst part is routing the brake cables through the frames because, unless you have the Formula Cura brakes with detachable lines, you will need to mess with brake fluid for sure (be it just a little drop or a full mess).