What's an idiom for doing something in an unnecessarily complicated way?

For an example, I'll quote C.S. Lewis' The Voyage of the Dawn Treader:

One day the cat got into the dairy and twenty of them were at work moving all the milk out; no one thought of moving the cat.

Is there an idiom for this type of situation?

Solution 1:

Depending on the specifics, one could use "taking the scenic route" to the solution.

This wouldn't work for the cat in the dairy, but it does work in problem solving for example.

An overly complicated device could be a Rube Goldberg machine. This could be used for a metaphorical machine as well, or one could use Rube Goldberg process.

Solution 2:

How about:

Swatting flies with a sledgehammer.

Although maybe that's more of an idiom for using the wrong tool, or for using unnecessary force, rather than for doing something in an unnecessarily complicated way.

EDIT: Actually, Google shows that this idiom has in fact been used with all three meanings.

Solution 3:

Not quite it perhaps, but my favorite expression for doing things the hard way is "Making love in a hammock. Standing up."