Structure Advice adding a door beneath a U-Shape Staircase

[peckhampouncer]

Hi,

Hoping to get some advice of Structural safety if I go ahead with what I have in mind.

I have a U Shape Staircase, i'm hoping to put a Door on one side (marked in purple),

However I'm worried if I take the bricks out i may make the brick walls holding up the stairs unsafe, any thoughts?

I will put a lintel across

Alex