...no, renaming won't help; but you can do the calculation with paper and pencil.
-> I've sent an image you by email.
You can do the calculation either in imperial or metric. Start at (A) or (G), and work down from there to the answer.
When a step says for example "L=I*K", it means "take the values from I and K, multiply, and name the answer L"... strictly speaking it's more of an assignment ("<-"), not an equation. If you have any questions, don't hesitate to ask me