In old houses, in summer cottages you can find such stairs
Try to upgrade to carry out modding in your haroms.
For example, to integrate diode backlighting, now the LEDs are not expensive and are sold in meters, and there are many different schemes for connecting to the Internet.
1. Drill holes for the LEDs
2. Install and connect the cables under the stairs.
Prepare blanks for new steps
1. Make one cardboard template with a large pitch.
2. Process all the steps (every second duplicate)
3. Align all steps if necessary.
Painting
To your taste.
Then paint them with parquet lacquer
Painting stairs in your favorite color
We put the stairs on the stairs
Fasten them to the screws
Upgrade or make a new handrail
Good modding!