Install Stata by following the Mac or Windows install instructions. NOTE: Make sure to select StataMP in step 4 of the instructions. If you don't, Stata won't work.
Using the license information from this page, follow the Mac or Windows license instructions to license Stata.
NOTE: If you don't see an Update license option in Stata in step 1 of the instructions below (because you have an older build of Stata), please follow these How to change license information instructions to put in new license codes to update the license.
Open Stata and go to Help --> About Stata --> Update license… --> Enter new license
Replace the existing license information with the new license information, click Next, and then click Finish.
Open Stata and it should now have the new license.