Acer R15 UEFi secure boot issues

Hello,

I have an acer R15 laptop (2016 model, i7 6500u, 12GB ram, 1TB hdd)

I installed Windows 10 in legacy mode so i could dual boot linux mint. However, i forgot to disable secure boot and i cannot get to any bios settings because Windows is legacy mode and Secure boot is enabled. How do i fix this? Should I clear the CMOS? Send it back to acer to fix? What do I do?