Try packing tape. Its a trainer.

Depending on the size of the holes, you can also just use covering to patch over the holes. You might want to confirm what brand of covering was used originally. If you use a higher heat range covering like monokote over the lower heat range coverings like ultracoat or aerocoat, you can melt holes in the original covering while trying to shrink the new covering. Ultracoat and Aerocoat on top of Monokote is fine.

Covering isn't hard. Don't let the hype stress you out.

Brad