any tips for playing the highest notes on clarinet?

basically as the title states - i have a piece that im learning for band and my part includes the five highest notes on clarinet which have been a little tricky to play, probably in part to the fact that ive never really had to play them so i obviously could use more practice but also.. theyre just kind of hard! also, are they supposed to be shrill? i feel like when i do get the note(s) off (rather than an obvious squeak) its a very shrill and annoying sound (truth be told idk why anyone would want to listen to it)