Yes, it isn't hard, but firstly use File > Save File As .. to create a COPY of your data file and do your experimenting on the COPY. That way you can't accidentally destroy your main file.
In the COPY, click File menu > Export > Partial > Select Now in the Field Filter area, click Define. On the next screen click RIN then click the ">" character. Select RIN > Is Greater Than (input the highest RIN you want to keep) > OK Now check the selected records to make sure you want to delete them, then click the Delete button and follow through. They will be gone from the COPY of your file.
Now is a good time to create a backup of the good data. If your data is the way you want it, make the COPY your main file. You will probably want to rename it.