Best way to think of Mirror Models are low-pressure injection moulded kits.
The earlier sprues have many heavy and larger connection points, relative to say Tamiya.
The plastic is a little brittle, but I recommend Trumpeter Razor Saw Tool Modeling Craft Model Kit DIY Accessories 09917, a few strokes & the parts fall off without shattering as they would if you used nippers.
Take your time as the instructions are a bit optimistic in places, but worth the effort.