1. Login to WHM as root
2. Go to Software -> EasyApache
3. If prompted to upgrade, do so then repeat step 2
4. Begin customizing based on the current provile
5. Proceed through the screens until you get to "Step 5"
6. On "Step 5," click on "Exhaustive Options"
7. Under PHP, check the checkbox for MBString
8. Proceed with Build & Compile Process
9. Make sure you wait for the build to complete.