I expect you'll have to create the letters with sketch geometry and then extrude them.
For the hollow effect on the X, I'd extrude it, then create a new sketch on the top face of the extrusion, project that face and offset in by how thick you want the border to be. Extrude again in the opposite direction. (i.e., if your X is raised, then extrude-cut to hollow it out, but if your X was recessed then use extrude-join.)
As for the 25, do the same thing, but you'll probably want to extrude to a different height so that it's offset visually from the X. (This assumes that you're going to be molding or machining the text in some way, I guess.)
Rusty