Here's my bash at it, took me a few goes to get it this far and it's probably wrong as I worked it out by ear, and I obviously didn't get around to working out the 2nd phrase before I started playing (there's my brick-headedness again).
The theme is actually taken from a piece called The Acrobat by J.A. Greenwood.
It's a fun piece to play, from the huge glissando right at the start (which is a challenge in itself - I'll sometimes drop a partial half way through the slide for added cringe-effect), the next few notes in the interleaved descending run can all be played at the same position which feels like it's good practice for getting a bit of control over my embouchure/partials, and the the middle up/down section is pretty fast and is a real stretch to tongue that quickly, ooo-er missus, and that second phrase where I don't know where I'm going has some notes that are [currently, for me at least] very high.
It's too easy to get drawn in to doing this stuff, both from the house renovation work that I should be focusing on, and from other chores like learning scales and doing my theory work etc.
Gonna need to find some discipline from somewhere (yeah, right). At least I did manage to start on my Trombone Essentials book at the weekend; grade 1 watch out - here I come... one day.
Here's my transcription of the theme, all errors are my own (click to embiggen):