problems trimming an oval

I'm trying to overlap some numbers, a Zero and a 5 so the numbers can be laser cut, all in one piece. So far I have been unsuccessful at trimming the two ovals that form the zero so the 5 is not a seperate piece, or destroying the 2 ovals? I have tried two line trim several times, but have been unsuccessful.

It is not clear what exactly you want to achieve. But anyway, if the numbers are from text, from a font, they can't be trimmed, as they are polylines. You have to explode them first.
Tools - Modify - Explode.
They cannot be edited as text anymore then, they are normal line, arc, circle entities.