How do I fix it?

My daughter's expensive CHI Rocket hair dryer failed because she had
not cleaned its (intake air) filter once in four years of almost daily
use, claiming its cap was difficult to twist off. The filter ended up
being almost totally plugged with dust, causing the dryer to overheat
from the reduced air flow, finally blowing the thermal fuse.

The dryer's case was difficult to open. I had to enlarge the crack
where the two halves joint with a hacksaw in order to use a flat head
screwdriver to pry them apart.There must be an easier way.I found it
to be well made with quality parts that should provide years of
trouble-free service. Unfortunately, because the thermal fuse is built
in to the heater assembly, it's inaccessible for replacement. Nowadays,
taking these things to a repair shop is out of the question given the
high cost of labour and parts. The only options were to toss it out and
buy another one, or try to repair it. I opted for the latter, soldering
in a wire shunt for the fuse, a finicky exercise as it turned out. It's
in the rear of the barrel where the heat shouldn't be high enough to
affect the solder. I've attached a plainly-visible warning note emphasizing
the importance of regularly inspecting and cleaning the air filter,
and I've blocked use of the high heat setting. I expect that with these
precautions there should be little or no chance of it overheating
enough to combust. Repair difficulty: about 3.5 out of 5.

William Easson
October 2019