In R, how do I find outliers in a multivariate regression?

My dataset is called "data" and my model name is m1. It includes 3 variables, called Rating, Reviews, and Mgb. Reviews is an integer value, whereas Rating and Mgb are both float values. My data is in a .csv format excel spreadsheet.

For a homework assignment, I need to find which rows in the spreadsheet are outliers without editing them in any way. In the next two questions, I need to find high leverage points and find influential points using Cook's distance. (I've already done that last one.) How do I do the first two?