Restoring Grub Launcher After Windows 10

I went ahead and installed windows 10 on my windows 8 and Ubuntu dual boot PC. All went smooth and Windows 10 works perfectly however the computer automatically boots to Windows and the grub launcher is missing. The partitions are still there I just need some help getting Ubuntu back. Thank you in advance!

Edit: I found a way around it. I don't know of this works for everyone but I went in to the control panel and went to update and recovery. Then I went to recovery and booted into uefi. Then I selected boot from device and my Ubuntu partition was there and I could boot into it. Feel free to post other solutions though!

Boot into Ubuntu using your computer's boot menu (probably something like press ESC at startup. it will tell you) and run this in Terminal:

sudo grub-install /dev/sda; sudo grub-mkconfig -o /boot/grub/grub.cfg