Use Self Service to submit midterm and final grades.
You will find Self Service on the Faculty Page in MyMeredith (requires login). On the Self Service menu, hover over Daily Work, then Faculty, then click on Faculty Overview. Click on the name of the course you are submitting grades for. It will open in Roster view. Click the tab that says "Grading." Enter the grades. There is no save or submit button.
For midterm grades, submit only Ds and Fs.
Meredith does not use +/- grading.
The academic calendar will give you the deadline for submitting midterm and final grades.