play it very slowly to start, then add speed later, a lot later from now. at least, thats how ive always tackled little problem passages like that.
I dont know if its a 4-5 trill or 2-3
I dont know what piece is it, but when I have some fast trills (for example c-d-c-d-...) in right hand I use: 1-3-1-2-1-3-1-2...
That's strange - wouldn't that make it harder to play with that fingering? I use 2-3-2-3I don't like 4-5 trills either. 2-3 is best for me.