Help with deleting fonts and themes on P8

[SlowInternet]

I would like to clear some space in the system folder of my Huawei P8. I have 126mb left in system ROM.I want to delete some of the themes and fonts. I have tried using File Explorer but when I want to delete the theme or font it says that they are read only.

Any help will be appreciated.

 

[Rickster]

ROM

Read Only Memory...

 

[SlowInternet]

Read Only Memory...

/hides from embarrassment