How to change partition from MBR to GUID?
I am trying to update to High Sierra but it won't let me because my disk is partitioned using MBR. I am kinda confused because even though i have recently installed a new hard disk, I have OS sierra running on the disk currently and my understanding is that OS sierra cannot run in MBR any more. Now i am faced with repartitioning my disk to GUID which i understand and acknowledge however when i go to disk utility i am not even able to select the partition panel for this disk. How do i repartition my main disk to GUID and reinstall the most recent version of OS sierra?? All the old articles give processes that are no longer relevant (i.e. use and install disk). Anyone help?
MacBook Pro (13-inch Early 2011), macOS Sierra (10.12.6)