There’s an awful lot to recommend this song. It’s a very sweet Christmas song. It references Stephin Merritt (I think). It was on the same Cherryade Christmas album as that Christmas song I sort of wrote the music for that one time. And it’s also only got three chords in.
The down side is that you need a capo on the second fret (or use D-tuning). But you can even skip that if you don’t mind singing it a tone lower.
You can use this as the main strumming pattern:
d – d – - u d u
Which sounds like this:
In the verse: do that once for every chord except the G at the end of the third line of each verse (where you do it twice).
In the middle: do eight down strums for the Cs and the main strum on the others.
The little xylophone bit transfers to uke well. Here it is assuming you’re capoed:
Without the capo, you can play it like this.