Converting parsecs to light years in the dumbest way possible
You asked for a dumb, tedious way of doing it. So here it is, in all its glory
One parsec is defined as $$\dfrac{1}{\tan(1'')} \text{ AU}=\dfrac{648000}{\pi} \text{ AU}$$
As $1 \text{ AU} = 149597870700 \text{ m}$, one parsec is equal to $$\dfrac{648000}{\pi} \cdot 149\,597\,870\,700 = \dfrac{96\,939\,420\,213\,600\,000}{\pi} \text{ m}$$
One light year can be calculated by multiplying $c$ by the number of seconds in a year: $$299792458 \cdot 86400 \cdot 365.25 = 9\,460\,730\,472\,580\,800 \text{ m}$$
Dividing the former by the latter, we get $\dfrac{1 \text{ pc}}{1 \text{ ly}} = 3.261564$