Good morning, I have managed to look up the model number - CH900K/GB
Is the replacement bulb identical to the one you removed or is it a different size\shape?
From what I can tell the bulb in your hood, has two pins rather than an screw fitting, is that correct?
What are you finding difficult is it getting it in place, to then fit into the fitting, or getting sufficient grip insert it into place?If you do indeed have a two pin bulb, you may find the video here useful. If the bulb has a screw terminal, you may find the video here useful.
I await to here back from you
You can use LED bulbs, which are often half the size, for example I use the bulbs here, which are equivalent to 8W, if you have enough room you could us the 15W bulb here.