1 As easy as changing a lightbulb
2 Still easy, but a bit more time consuming
3 May involve installing more complex devices, making simple parts, some ladder work, or working in dusty or awkward places
4 Like 3, but a bit more complex or time consuming
5–7 Projects require some design and planning, and mechanical or carpentry skills
8–9 A good challenge for almost any DIYer
10 Nearly impossible for ordinary mortals
