It is not hard to score.
First start with the basic stuff, that is, definitions, laws, etc. and understand their meaning.
Next part involves all the important derivations. For this, understand what has been asked to derive. Then, go through the entire derivation and practice it 2-3 times untill you are comfortable with it.
Then, move on to the numericals. This is very important aspect. For this, write down the given data. Understand what has been asked to solve. Then, judge the formula based on the given data and the thing to be found. Then, solve the numerical.