I fast sewed the hole in hand, then placed a piece of fabric on it and drew a picture I'd found on the Net.

I sewed it with a black zigg zagg stitch as an application. Then I followed the lines, with simple red straight stitch, to match the rest of denims.

It was a good exercise for me not to forget what I learned at gryffins:-)
You can take a look at how big the hole was. I didn't find any other way but application..

Dad put them on the following day. I mentioned the hole and he said that he knew about it, but didn't have time to sew it yet. He didn't notice! :-D :-D :-D