I need help converting this cartesian equation:

0.2025=x^{2}+(y+1.5)^{2}

into this polar equation:

r=-sqrt(2.25(sin(theta)^{2})-2.05)-1.5sin(theta)

What steps do I need to take to convert the first equation to the second one? Please help explain this to me; a step by step walkthrough would be greatly appreciated. Thank you.