The next step will be to extrude the lettering to make it thick. To extrude the lettering the right direction, you will first have to find the direction that is normal (perpendicular) to the surface.
Use the Normal command to draw a line from the letter surface.
Pick a point on the surface that is near the center of the letter.
The length of the line does not matter.
Use the ExtrudeSrf command to make the letter thick.
At the Select surfaces to extrude prompt, select one of the letter surfaces and press Enter.
Since each letter will be extruded in a different direction, you will extrude each letter individually.
At the Extrusion distance < 0.1 > ( Direction ) prompt, type D.
At the Base point of extrusion ( Vertical ) prompt, use the Endpoint object snap to select the end of the normal line that is on the surface.
At the Direction prompt, use the Endpoint object snap to select the other end of the line.
At the Extrusion distance < 0.1 > ( Direction ) prompt, enter .1.
Repeat these steps for the other letters.